Revert "Improve MALLOC_DEBUG"

This reverts commit 4b3e65682d.

malloc/malloc.c

@@ -3456,6 +3456,8 @@ __libc_free (void *mem)
   if (__glibc_unlikely (misaligned_chunk (p)))
     return malloc_printerr_tail ("free(): invalid pointer");
 
+  check_inuse_chunk (arena_for_chunk (p), p);
+
 #if USE_TCACHE
   if (__glibc_likely (size < mp_.tcache_max_bytes && tcache != NULL))
     {
@@ -4678,8 +4680,6 @@ _int_free_merge_chunk (mstate av, mchunkptr p, INTERNAL_SIZE_T size)
 {
   mchunkptr nextchunk = chunk_at_offset(p, size);
 
-  check_inuse_chunk (av, p);
-
   /* Lightweight tests: check whether the block is already the
      top block.  */
   if (__glibc_unlikely (p == av->top))