[fix][doc]Correcting spelling mistakes in the pulsar-broker module

pulsar-broker/src/main/java/org/apache/pulsar/PulsarClusterMetadataSetup.java

@@ -281,7 +281,7 @@ public static void main(String[] args) throws Exception {
         try {
             initializeCluster(arguments, bundleNumberForDefaultNamespace);
         } catch (Exception e) {
-            System.err.println("Unexpected error occured.");
+            System.err.println("Unexpected error occurred.");
             e.printStackTrace(System.err);
             System.err.println("Terminating JVM...");
             ShutdownUtil.triggerImmediateForcefulShutdown();

pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/LinuxBrokerHostUsageImpl.java

@@ -155,7 +155,7 @@ private double getTotalCpuUsageForCGroup(double elapsedTimeSeconds) {
      * </pre>
      *
      * Line is split in "words", filtering the first. The sum of all numbers give the amount of cpu cycles used this
-     * far. Real CPU usage should equal the sum substracting the idle cycles(that is idle+iowait), this would include
+     * far. Real CPU usage should equal the sum subtracting the idle cycles(that is idle+iowait), this would include
      * cpu, user, nice, system, irq, softirq, steal, guest and guest_nice.
      */
     private double getTotalCpuUsageForEntireHost() {

pulsar-broker/src/main/java/org/apache/pulsar/broker/qos/AsyncTokenBucket.java

@@ -257,7 +257,7 @@ public boolean consumeTokensAndCheckIfContainsTokens(long consumeTokens) {
         } else if (currentTokens == Long.MIN_VALUE) {
             // when currentTokens is Long.MIN_VALUE, the current tokens balance is unknown since consumed tokens
             // was added to the pendingConsumedTokens LongAdder counter. In this case, assume that tokens balance
-            // hasn't been updated yet and calculate a best guess of the current value by substracting the consumed
+            // hasn't been updated yet and calculate a best guess of the current value by subtracting the consumed
             // tokens from the current tokens balance
             return tokens - consumeTokens > 0;
         } else {

pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentTopic.java

@@ -328,7 +328,7 @@ private static class EstimateTimeBasedBacklogQuotaCheckResult {
      * 2. Namespace bundle transfer or unloading.
      *   a. The unloading topic triggered by unloading namespace bundles will not wait for clients disconnect. Relate
      *     to {@link CloseFutures#notWaitDisconnectClients}.
-     *   b. The unloading topic triggered by unloading namespace bundles was seperated to two steps when using
+     *   b. The unloading topic triggered by unloading namespace bundles was separated to two steps when using
      *     {@link ExtensibleLoadManagerImpl}.
      *     b-1. step-1: fence the topic on the original Broker, and do not trigger reconnections of clients. Relate
      *       to {@link CloseFutures#transferring}. This step is a half closing.
@@ -3140,7 +3140,7 @@ public void checkGC() {
                  *   "replicator.producer" to a null value.
                  * Race condition: task 1 will get a NPE when it tries to send messages using the variable
                  * "replicator.producer", because task 2 will set this variable to "null".
-                 * TODO Create a seperated PR to fix it.
+                 * TODO Create a separated PR to fix it.
                  */
                 closeReplProducersIfNoBacklog().thenRun(() -> {
                     if (hasRemoteProducers()) {

pulsar-broker/src/test/java/org/apache/pulsar/broker/admin/GetPartitionMetadataMultiBrokerTest.java

@@ -135,7 +135,7 @@ protected void verifyPartitionsNeverCreated(String topicNameStr) throws Exceptio
         } catch (Exception ex) {
             // If the namespace bundle has not been loaded yet, it means no non-persistent topic was created. So
             //   this behavior is also correct.
-            // This error is not expected, a seperated PR is needed to fix this issue.
+            // This error is not expected, a separated PR is needed to fix this issue.
             assertTrue(ex.getMessage().contains("Failed to find ownership for"));
         }
     }
@@ -148,7 +148,7 @@ protected void verifyNonPartitionedTopicNeverCreated(String topicNameStr) throws
         } catch (Exception ex) {
             // If the namespace bundle has not been loaded yet, it means no non-persistent topic was created. So
             //   this behavior is also correct.
-            // This error is not expected, a seperated PR is needed to fix this issue.
+            // This error is not expected, a separated PR is needed to fix this issue.
             assertTrue(ex.getMessage().contains("Failed to find ownership for"));
         }
     }