BUG#20528 Added missing parenthesis to DBUG_PRINT statement

mysys/my_lib.c

@@ -501,7 +501,7 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
   if (!(MyFlags & MY_DONT_SORT))
     qsort((void *) result->dir_entry, result->number_off_files,
           sizeof(FILEINFO), (qsort_cmp) comp_names);
-  DBUG_PRINT(exit, ("found %d files", result->number_off_files));
+  DBUG_PRINT("exit", ("found %d files", result->number_off_files));
   DBUG_RETURN(result);
 error:
   my_errno=errno;