media: ov9640: Don't set format in sub-device state

For the purpose of setting old non-pad based sub-device try format as a
basis for VIDIOC_TRY_FMT implementation, there is no need to set the
format in the sub-device state. Drop the assignment to the state, which
would result in a NULL pointer dereference.

Fixes: fd17e3a9

 ("media: i2c: Use accessors for pad config 'try_*' fields")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>