staging: ralink-gdma: Check return code of device_reset

The device_reset() function is marked as "__must_check", thus the static
analysis tool "sparse" complains that in ralink-gdma its return value is
ignored. Log a warning in case it returns an error.

Signed-off-by: Giovanni Gherdovich <bobdc9664@seznam.cz>
Link: https://lore.kernel.org/r/20210306141322.7516-1-bobdc9664@seznam.cz


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>