patch-ids: replace the seen indicator with a commit pointer

The cherry_pick_list was looping through the original side checking the
seen indicator and setting the cherry_flag on the commit.  If we save
off the commit in the patch_id we can set the cherry_flag on the correct
commit when running through the other side when a patch_id match is found.

Signed-off-by: Kevin Willford <kcwillford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/patch-ids.c b/patch-ids.c
index db31fa6..bafaae2 100644
--- a/patch-ids.c
+++ b/patch-ids.c
@@ -43,6 +43,7 @@
 			       struct commit *commit,
 			       struct patch_ids *ids)
 {
+	patch->commit = commit;
 	if (commit_patch_id(commit, &ids->diffopts, patch->patch_id))
 		return -1;