dmaengine: coh901318: Fix a double lock bug in dma_tc_handle()

BugLink: https://bugs.launchpad.net/bugs/1868628

commit 36d5d220 upstream.

The caller is already holding the lock so this will deadlock.

Fixes: 0b58828c ("DMAENGINE: COH 901 318 remove irq counting")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200217144050.3i4ymbytogod4ijn@kili.mountainSigned-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

drivers/dma/coh901318.c

@@ -1960,8 +1960,6 @@ static void dma_tc_handle(struct coh901318_chan *cohc)
 		return;
 	}
 
-	spin_lock(&cohc->lock);
-
 	/*
 	 * When we reach this point, at least one queue item
 	 * should have been moved over from cohc->queue to
@@ -1982,8 +1980,6 @@ static void dma_tc_handle(struct coh901318_chan *cohc)
 	if (coh901318_queue_start(cohc) == NULL)
 		cohc->busy = 0;
 
-	spin_unlock(&cohc->lock);
-
 	/*
 	 * This tasklet will remove items from cohc->active
 	 * and thus terminates them.