soundwire: (cosmetic) remove multiple superfluous "else" statements

No need for an "else" after a "return" statement. Remove multiple such
occurrences in bus.c.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200508003046.23162-2-guennadi.liakhovetski@linux.intel.com


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