soundwire: cadence: Fix error check in cdns_xfer_msg()

_cdns_xfer_msg() returns an sdw_command_response value, not a
negative error code.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220917154822.690472-1-rf@opensource.cirrus.com


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