dmaengine: apple-admac: Fix 'current_tx' not getting freed

[ Upstream commit d9503be5 ]

In terminate_all we should queue up all submitted descriptors to be
freed. We do that for the content of the 'issued' and 'submitted' lists,
but the 'current_tx' descriptor falls through the cracks as it's
removed from the 'issued' list once it gets assigned to be the current
descriptor. Explicitly queue up freeing of the 'current_tx' descriptor
to address a memory leak that is otherwise present.

Fixes: b127315d

 ("dmaengine: apple-admac: Add Apple ADMAC driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20230224152222.26732-2-povik+lin@cutebit.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>