Use MOVE_ARRAY

Use the helper macro MOVE_ARRAY to move arrays.  This is shorter and
safer, as it automatically infers the size of elements.

Patch generated by Coccinelle and contrib/coccinelle/array.cocci in
Travis CI's static analysis build job.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/commit.c b/commit.c
index cab8d44..7d00801 100644
--- a/commit.c
+++ b/commit.c
@@ -126,10 +126,8 @@ int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 	ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 	commit_graft_nr++;
 	if (pos < commit_graft_nr)
-		memmove(commit_graft + pos + 1,
-			commit_graft + pos,
-			(commit_graft_nr - pos - 1) *
-			sizeof(*commit_graft));
+		MOVE_ARRAY(commit_graft + pos + 1, commit_graft + pos,
+			   commit_graft_nr - pos - 1);
 	commit_graft[pos] = graft;
 	return 0;
 }