mtd_blkdevs.c: quiet a "symbol shadows" sparse warning

In register_mtd_blktrans(), the symbol 'ret' is already declared
as an int at the start of the function.  The inner loop declaration
is unnecessary.  Quiets the following sparse warning:

  warning: symbol 'ret' shadows an earlier one
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtd_blkdevs.c

@@ -388,7 +388,7 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 	tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,
 			"%sd", tr->name);
 	if (IS_ERR(tr->blkcore_priv->thread)) {
-		int ret = PTR_ERR(tr->blkcore_priv->thread);
+		ret = PTR_ERR(tr->blkcore_priv->thread);
 		blk_cleanup_queue(tr->blkcore_priv->rq);
 		unregister_blkdev(tr->major, tr->name);
 		kfree(tr->blkcore_priv);