[media] smiapp: Fix error handling in power on sequence

The error handling code in smiapp_power_on() returned in case of a failed
I2C write instead of cleaning up the mess. Fix this.

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