[media] smiapp: Clean up smiapp_init_controls()

Clean up smiapp_init_controls() by adding newlines to appropriate places and
by removing superfluous error handling. The caller will clean up control
handlers in any case if the function fails.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>