staging: bcm2835-camera: Check the error for REPEAT_SEQ_HEADER (#2782)

staging: bcm2835-camera: Check the error for REPEAT_SEQ_HEADER (#2782)

When handling for V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER was added
the firmware would reject the setting if H264 hadn't already been
selected. This was fixed in the firmware at that point, but to
enable backwards compatibility the returned error was ignored.

That was Dec 2013, so the chances of having a firmware that still
has that issue is so close to zero that the workaround can be
removed.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>