malloc: fix the range check of the memory block address inside a non-big block

src/malloc.c

@@ -61,7 +61,7 @@ void * malloc(size_t size) {
             /* Check that a valid pointer has been returned */
             assert(((uintptr_t) raw_block < (uintptr_t) ptr) &&
                     ((uintptr_t) ptr < (uintptr_t) raw_block +
-                     raw_block->size));
+                     raw_block->size + sizeof(raw_block_header_t)));
             break;
         }
     }