Report symlink failures in merge-recursive

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

merge-recursive.c

@@ -525,7 +525,8 @@ static void update_file_flags(struct merge_options *o,
 			char *lnk = xmemdupz(buf, size);
 			safe_create_leading_directories_const(path);
 			unlink(path);
-			symlink(lnk, path);
+			if (symlink(lnk, path))
+				die("failed to symlink %s: %s", path, strerror(errno));
 			free(lnk);
 		} else
 			die("do not know what to do with %06o %s '%s'",