memstick/ms_block: Use the bitmap API when applicable

Use bitmap_equal() instead of hand writing it. It improves semantic and
avoids some explicit computation to convert a number of bits to a number of
bytes.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/b216df8798f765ab14bce65739c220643320f376.1656155715.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: tititiou36

drivers/memstick/core/ms_block.c

@@ -2245,8 +2245,8 @@ static int msb_resume(struct memstick_dev *card)
 		goto out;
 
 	if (msb->block_count != new_msb->block_count ||
-		memcmp(msb->used_blocks_bitmap, new_msb->used_blocks_bitmap,
-							msb->block_count / 8))
+	    !bitmap_equal(msb->used_blocks_bitmap, new_msb->used_blocks_bitmap,
+							msb->block_count))
 		goto out;
 
 	card_dead = false;