[dvb saa7134] Fix missing 'break' for avermedia card case

Commit 450efcfd broke Avermedia 777
support.

Added obvious missing "break" statement.

Cc: Jos Surez <j.suarez.agapito@gmail.com>
Cc: Michael Krufky <mkrufky@linuxtv.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>