commit: allow lookup_commit_graft to handle arbitrary repositories

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/commit.h b/commit.h
index 45114a9..6de6f10 100644
--- a/commit.h
+++ b/commit.h
@@ -175,8 +175,7 @@ typedef int (*each_commit_graft_fn)(const struct commit_graft *, void *);
 
 struct commit_graft *read_graft_line(struct strbuf *line);
 int register_commit_graft(struct repository *r, struct commit_graft *, int);
-#define lookup_commit_graft(r, o) lookup_commit_graft_##r(o)
-struct commit_graft *lookup_commit_graft_the_repository(const struct object_id *oid);
+struct commit_graft *lookup_commit_graft(struct repository *r, const struct object_id *oid);
 
 extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2);
 extern struct commit_list *get_merge_bases_many(struct commit *one, int n, struct commit **twos);