convert read_cache_preload() to take struct pathspec

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/diff.c b/builtin/diff.c
index 6bb41af..bb84ba0 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -140,7 +140,7 @@
 		usage(builtin_diff_usage);
 	if (!cached) {
 		setup_work_tree();
-		if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
+		if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 			perror("read_cache_preload");
 			return -1;
 		}
@@ -242,7 +242,7 @@
 		revs->combine_merges = revs->dense_combined_merges = 1;
 
 	setup_work_tree();
-	if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
+	if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 		perror("read_cache_preload");
 		return -1;
 	}