net: caif: spi: fix potential NULL dereference

alloc_netdev() is not checked here for NULL return value.  dev is
check instead.  It might lead to NULL dereference of ndev.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/caif/caif_spi.c
Simple merge