8345758: AArch64: vm_version_linux_aarch64.cpp report nullptr compile warning by gcc14

Author: sendaoYan

src/hotspot/os_cpu/linux_aarch64/vm_version_linux_aarch64.cpp

@@ -185,7 +185,10 @@ static bool read_fully(const char *fname, char *buf, size_t buflen) {
   assert(buflen >= 1, "invalid argument");
   int fd = os::open(fname, O_RDONLY, 0);
   if (fd != -1) {
+    PRAGMA_DIAG_PUSH
+    PRAGMA_NONNULL_IGNORED
     ssize_t read_sz = ::read(fd, buf, buflen);
+    PRAGMA_DIAG_POP
     ::close(fd);
 
     // Skip if the contents is just "\n" because some machine only sets