[media] soc-camera: fix uninitialized warning

This fixes the following compilation warning:

  drivers/media/platform/soc_camera/soc_camera.c: In function ‘soc_camera_host_register’:
  drivers/media/platform/soc_camera/soc_camera.c:1514:55: warning: ‘sasd’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  drivers/media/platform/soc_camera/soc_camera.c:1464:34: note: ‘sasd’ was declared here

Signed-off-by: Vincent Stehlé <vincent.stehle@freescale.com>