V4L/DVB (9635): v4l: s2255drv fix firmware test on big-endian

Noticed by sparse:
drivers/media/video/s2255drv.c:2531:6: warning: restricted __le32 degrades to integer

Cc: Dean Anderson <dean@sensoray.com>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>