commit: add repository argument to lookup_commit_reference_gently

Add a repository argument to allow callers of
lookup_commit_reference_gently to be more specific about which
repository to handle. This is a small mechanical change; it doesn't
change the implementation to handle repositories other than
the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/notes-cache.c b/notes-cache.c
index d577003..d87e7ca 100644
--- a/notes-cache.c
+++ b/notes-cache.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "notes-cache.h"
 #include "object-store.h"
+#include "repository.h"
 #include "commit.h"
 #include "refs.h"
 
@@ -15,7 +16,7 @@ static int notes_cache_match_validity(const char *ref, const char *validity)
 	if (read_ref(ref, &oid) < 0)
 		return 0;
 
-	commit = lookup_commit_reference_gently(&oid, 1);
+	commit = lookup_commit_reference_gently(the_repository, &oid, 1);
 	if (!commit)
 		return 0;