dmaengine: sh: Discard pm_runtime_put() return value

dmaengine: sh: Discard pm_runtime_put() return value

Clobbering an error value to be returned from shdma_tx_submit() with
a pm_runtime_put() return value is not particularly useful, especially
if the latter is 0, so stop doing that.

This will facilitate a planned change of the pm_runtime_put() return
type to void in the future.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/9626129.rMLUfLXkoz@rafael.j.wysocki
Signed-off-by: Vinod Koul <vkoul@kernel.org>