mmc: fix null pointer use in mmc_blk_remove_req

A previous commit (fdfa20c1) reordered the shutdown sequence
in mmc_blk_remove_req. However, mmc_cleanup_queue is now called before
we get the card pointer, and mmc_cleanup_queue sets mq->card to NULL.

This patch moves the card pointer assignment before mmc_cleanup_queue.
Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/card/block.c

@@ -2230,10 +2230,10 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
 		 * is freeing the queue that stops new requests
 		 * from being accepted.
 		 */
+		card = md->queue.card;
 		mmc_cleanup_queue(&md->queue);
 		if (md->flags & MMC_BLK_PACKED_CMD)
 			mmc_packed_clean(&md->queue);
-		card = md->queue.card;
 		if (md->disk->flags & GENHD_FL_UP) {
 			device_remove_file(disk_to_dev(md->disk), &md->force_ro);
 			if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&