builtin/pack-objects.c: use die_errno() and warning_errno()

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

builtin/pack-objects.c

@@ -828,8 +828,7 @@ static void write_pack_file(void)
 			 * to preserve this property.
 			 */
 			if (stat(pack_tmp_name, &st) < 0) {
-				warning("failed to stat %s: %s",
-					pack_tmp_name, strerror(errno));
+				warning_errno("failed to stat %s", pack_tmp_name);
 			} else if (!last_mtime) {
 				last_mtime = st.st_mtime;
 			} else {
@@ -837,8 +836,7 @@ static void write_pack_file(void)
 				utb.actime = st.st_atime;
 				utb.modtime = --last_mtime;
 				if (utime(pack_tmp_name, &utb) < 0)
-					warning("failed utime() on %s: %s",
-						pack_tmp_name, strerror(errno));
+					warning_errno("failed utime() on %s", pack_tmp_name);
 			}
 
 			strbuf_addf(&tmpname, "%s-", base_name);