hashmap: remove type arg from hashmap_{get,put,remove}_entry

Since these macros already take a `keyvar' pointer of a known type,
we can rely on OFFSETOF_VAR to get the correct offset without
relying on non-portable `__typeof__' and `offsetof'.

Argument order is also rearranged, so `keyvar' and `member' are
sequential as they are used as: `keyvar->member'

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/patch-ids.c b/patch-ids.c
index af17828..12aa6d4 100644
--- a/patch-ids.c
+++ b/patch-ids.c
@@ -101,8 +101,7 @@ struct patch_id *has_commit_patch_id(struct commit *commit,
 	if (init_patch_id_entry(&patch, commit, ids))
 		return NULL;
 
-	return hashmap_get_entry(&ids->patches, &patch, NULL,
-					struct patch_id, ent);
+	return hashmap_get_entry(&ids->patches, &patch, ent, NULL);
 }
 
 struct patch_id *add_commit_patch_id(struct commit *commit,