NLM: Fix a regression in lockd

Nick Bowler reports:
There are no unusual messages on the client... but I just logged into
the server and I see lots of messages of the following form:

  nfsd: request from insecure port (192.168.8.199:35766)!
  nfsd: request from insecure port (192.168.8.199:35766)!
  nfsd: request from insecure port (192.168.8.199:35766)!
  nfsd: request from insecure port (192.168.8.199:35766)!
  nfsd: request from insecure port (192.168.8.199:35766)!

Bisected to commit 92476850 (SUNRPC:
Properly initialize sock_xprt.srcaddr in all cases)

Apparently, removing the 'transport->srcaddr.ss_family = family' from
xs_create_sock() triggers this due to nlmclnt_lookup_host() incorrectly
initialising the srcaddr family to AF_UNSPEC.

Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>