combine-diff.c: use error_errno()

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

combine-diff.c

@@ -1005,8 +1005,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 			struct strbuf buf = STRBUF_INIT;
 
 			if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
-				error("readlink(%s): %s", elem->path,
+				error_errno("readlink(%s)", elem->path);
-				      strerror(errno));
 				return;
 			}
 			result_size = buf.len;