Since xfrm_user can be built as a module it's best not to panic
when something goes wrong in xfrm_user_init.  Call me a wimp for
not fixing netlink_kernel_init's return value :)
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>