Fix checkstyle & apply suggestions

Author: Fabricio Duarte

engine/orchestration/src/main/java/org/apache/cloudstack/engine/orchestration/StorageOrchestrator.java

@@ -27,7 +27,6 @@
 import java.util.Map;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.Callable;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.ThreadPoolExecutor;
@@ -359,7 +358,7 @@ protected Map<Long, Pair<Long, Long>> migrateAway(
 
     protected synchronized <T> Future<T> submit(Long zoneId, Callable<T> task) {
         if (!zoneExecutorMap.containsKey(zoneId)) {
-            zoneExecutorMap.put(zoneId, new ThreadPoolExecutor(numConcurrentCopyTasksPerSSVM , numConcurrentCopyTasksPerSSVM,
+            zoneExecutorMap.put(zoneId, new ThreadPoolExecutor(numConcurrentCopyTasksPerSSVM, numConcurrentCopyTasksPerSSVM,
                     30, TimeUnit.MINUTES, new MigrateBlockingQueue<>(numConcurrentCopyTasksPerSSVM)));
         }
         scaleExecutorIfNecessary(zoneId);