lockd: Remove src_sap and src_len from nlm_lookup_host_info struct

Clean up.

The contents of the src_sap field is not used in nlm_alloc_host().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>