cocci: apply the "cache.h" part of "the_repository.pending"

Apply the part of "the_repository.pending.cocci" pertaining to
"cache.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/mailmap.c b/mailmap.c
index da2589b..ed8289a 100644
--- a/mailmap.c
+++ b/mailmap.c
@@ -213,7 +213,7 @@ static int read_mailmap_blob(struct string_list *map, const char *name)
 
 	if (!name)
 		return 0;
-	if (get_oid(name, &oid) < 0)
+	if (repo_get_oid(the_repository, name, &oid) < 0)
 		return 0;
 
 	buf = read_object_file(&oid, &type, &size);