mv: combine two if(s)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/mv.c

@@ -274,10 +274,9 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 	if (gitmodules_modified)
 		stage_updated_gitmodules();
 
-	if (active_cache_changed) {
+	if (active_cache_changed &&
-		if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
+	    write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
-			die(_("Unable to write new index file"));
+		die(_("Unable to write new index file"));
-	}
 
 	return 0;
 }