dmaengine: fsl-qdma: fix duplicated argument to &&

dmaengine: fsl-qdma: fix duplicated argument to &&

There is duplicated argument to && in function fsl_qdma_free_chan_resources,
which looks like a typo, pointer fsl_queue->desc_pool also needs NULL check,
fix it.
Detected with coccinelle.

Fixes: a25617b24728 ("dmaengine: fsl-qdma: Add qDMA controller driver for Layerscape SoCs")
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Reviewed-by: Peng Ma <peng.ma@nxp.com>
Tested-by: Peng Ma <peng.ma@nxp.com>
Link: https://lore.kernel.org/r/20200120125843.34398-1-chenzhou10@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>