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/rerere.c b/rerere.c
index 1ce440f..79203c6 100644
--- a/rerere.c
+++ b/rerere.c
@@ -159,8 +159,8 @@ static struct rerere_dir *find_rerere_dir(const char *hex)
 		ALLOC_GROW(rerere_dir, rerere_dir_nr + 1, rerere_dir_alloc);
 		/* ... and add it in. */
 		rerere_dir_nr++;
-		memmove(rerere_dir + pos + 1, rerere_dir + pos,
-			(rerere_dir_nr - pos - 1) * sizeof(*rerere_dir));
+		MOVE_ARRAY(rerere_dir + pos + 1, rerere_dir + pos,
+			   rerere_dir_nr - pos - 1);
 		rerere_dir[pos] = rr_dir;
 		scan_rerere_dir(rr_dir);
 	}