optimized amFree even further

src/module.c

@@ -585,12 +585,17 @@ void autoMemoryFreed(RedisModuleCtx *ctx, int type, void *ptr) {
             ctx->amqueue[j].ptr == ptr)
         {
             ctx->amqueue[j].type = REDISMODULE_AM_FREED;
-            /* Optimization: if this is the last element, we can
+            
-             * reuse it. */
+            /* Switch the freed element and the top element, to avoid growing
-            if (j == ctx->amqueue_used-1) ctx->amqueue_used--;
+             * the queue unnecessarily if we allocate/free in a loop */
+            if (j != ctx->amqueue_used-1) {
+                ctx->amqueue[j] = ctx->amqueue[ctx->amqueue_used-1];
+            }
+            /* Reduce the size of the queue because we either moved the top
+             * element elsewhere or freed it */ 
+            ctx->amqueue_used--;
 
             break;
-
         }
     }
 }