MINOR: fix getNormalBufferCount

This used to return size, which is wrong.

Author: no23reason

memory/memory-netty-buffer-patch/src/main/java/io/netty/buffer/PooledByteBufAllocatorL.java

@@ -82,7 +82,7 @@ public long getNormalBufferSize() {
   }
 
   public long getNormalBufferCount() {
-    return normalBufferSize.get();
+    return normalBufferCount.get();
   }
 
   private static class AccountedUnsafeDirectLittleEndian extends UnsafeDirectLittleEndian {