[media] s3c-camif: fix compiler warnings

[media] s3c-camif: fix compiler warnings

Fix these compiler warnings that appeared after switching to gcc-5.1.0:

drivers/media/platform/s3c-camif/camif-capture.c: In function 'sensor_set_power':
drivers/media/platform/s3c-camif/camif-capture.c:118:10: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses]
  if (!on == camif->sensor.power_count)
          ^
drivers/media/platform/s3c-camif/camif-capture.c: In function 'sensor_set_streaming':
drivers/media/platform/s3c-camif/camif-capture.c:134:10: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses]
  if (!on == camif->sensor.stream_count)
          ^

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>