V4L/DVB (7236): bttv: struct member initialized twice

fixes sparse warning:
drivers/media/video/bt8xx/bttv-driver.c:3391:3: warning: Initializer entry defined twice
drivers/media/video/bt8xx/bttv-driver.c:3392:3:   also defined here

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@infradead.org>