If via_ircc_open() fails, data structures of the driver left uninitialized,
but probe (via_init_one()) returns zero. That can lead to null pointer dereference
in via_remove_one(), since it does not check drvdata for NULL.

The patch implements proper error code propagation.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>