dmaengine: ti: omap-dma: Remove 'Assignment in if condition'

While the compiler does not have problem with how it is implemented,
checkpatch does give en ERROR for this arrangement.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20190730132015.2863-1-peter.ujfalusi@ti.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>