USB: staging: media: as102: convert to use module_usb_driver

The as102 driver can be converted to use module_usb_driver() which saves
a lot of code, and gets rid of an unwanted err() call at the same time.

Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Sylwester Nawrocki <snjw23@gmail.com>
Cc: Piotr Chmura <chmooreck@poczta.onet.pl>
Cc: Devin Heitmueller <dheitmueller@kernellabs.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>