dmaengine: idxd: Delete unnecessary NULL check

The "saved_evl" pointer is a offset into the middle of a non-NULL struct.
It can't be NULL and the check is slightly confusing.  Delete the check.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/ec38214e-0bbb-4c5a-94ff-b2b2d4c3f245@stanley.mountain


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