ASoC: imx-pcm-rpmsg: Remove unused variable

Variable ret is initialed but is never modified or used except for
returning the initial value 0. The value can be directly returned
instead and the variable definition can be dropped.
Issue identified using returnvar.cocci Coccinelle semantic patch.

Signed-off-by: Deepak R Varma <drv@mailo.com>
Link: https://lore.kernel.org/r/Y+p9r5y9DPSJkPVf@ubun2204.myguest.virtualbox.org


Signed-off-by: Mark Brown <broonie@kernel.org>