fix up strtoul_ui error handling

Two scanf() calls were converted to strtoul_ui() but the return
values were not updated to match.  scanf() returns the number of
matched "values" which for this usage is 1 on success.  strtoul_ui()
return 0 on success.  Update these call sites to match.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/builtin-update-index.c b/builtin-update-index.c
index 6ed61eb..8659800 100644
--- a/builtin-update-index.c
+++ b/builtin-update-index.c
@@ -551,7 +551,7 @@
 				if (i+3 >= argc)
 					die("git-update-index: --cacheinfo <mode> <sha1> <path>");
 
-				if ((strtoul_ui(argv[i+1], 8, &mode) != 1) ||
+				if (strtoul_ui(argv[i+1], 8, &mode) ||
 				    get_sha1_hex(argv[i+2], sha1) ||
 				    add_cacheinfo(mode, sha1, argv[i+3], 0))
 					die("git-update-index: --cacheinfo"