dmaengine: at_xdmac: remove a stray bottom half unlock

We switched this code from spin_lock_bh() to vanilla spin_lock() but
there was one stray spin_unlock_bh() that was overlooked.  This
patch converts it to spin_unlock() as well.

Fixes: d8570d01 ("dmaengine: at_xdmac: move spin_lock_bh to spin_lock in tasklet")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/at_xdmac.c

@@ -1655,7 +1655,7 @@ static void at_xdmac_tasklet(unsigned long data)
 		dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
 		if (!desc->active_xfer) {
 			dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
-			spin_unlock_bh(&atchan->lock);
+			spin_unlock(&atchan->lock);
 			return;
 		}