[media] media: soc-camera: remove superfluous JPEG checking

Explicit checks for the JPEG pixel format in soc_mbus_bytes_per_line() and
soc_mbus_image_size() are superfluous, because also without them these
functions will perform correctly. The former will return 0 based on
packing == SOC_MBUS_PACKING_VARIABLE and the latter will simply multiply
the user-provided line length by the image height to obtain a frame buffer
size estimate. The original version of the "media: soc_camera: don't clear
pix->sizeimage in JPEG mode" patch was correct and my amendment, adding
these two checks was superfluous.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>