8320916: jdk/jfr/event/gc/stacktrace/TestParallelMarkSweepAllocationPendingStackTrace.java failed with "OutOfMemoryError: GC overhead limit exceeded"

Backport-of: 693847452f208446a34186f142fe2c56a49ceceb

Author: SendaoYan

test/jdk/jdk/jfr/event/gc/stacktrace/AllocationStackTrace.java

@@ -81,15 +81,15 @@ public void allocate() {
 class OldGenMemoryAllocator extends MemoryAllocator {
 
     private List<byte[]> list = new ArrayList<byte[]>();
-    private int counter = 6000;
+    private int counter = 5000;
 
     @Override
     public void allocate() {
         if (counter-- > 0) {
             list.add(new byte[10 * KB]);
         } else {
             list = new ArrayList<byte[]>();
-            counter = 6000;
+            counter = 5000;
         }
 
         garbage = list;