ser_gigaset: return -ENOMEM on error instead of success

ser_gigaset: return -ENOMEM on error instead of success

BugLink: http://bugs.launchpad.net/bugs/1656876
[ Upstream commit 93a97c50cbf1c007caf12db5cc23e0d5b9c8473c ]

If we can't allocate the resources in gigaset_initdriver() then we
should return -ENOMEM instead of zero.

Fixes: 2869b23e4b95 ("[PATCH] drivers/isdn/gigaset: new M101 driver (v2)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>