V4L/DVB (4368): Bttv: use class_device_create_file and handle errors

Revert bttv-driver.c from video_device_create_file() to use
class_device_create_file() again.  video_device_create_file() is only
available when V4L1 is on.
Proper error checking is added for failure of class_device_create_file().
Will print error message and unroll partially created sysfs entries.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>