USB: as102_usb_drv.c: remove err() usage

err() was a very old USB-specific macro that I thought had
gone away.  This patch removes it from being used in the
driver and uses dev_err() instead.

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: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>