nfsd/sunrpc: move sv_module parm into sv_ops

...not technically an operation, but it's more convenient and cleaner
to pass the module pointer in this struct.

Signed-off-by: Shirley Ma <shirley.ma@oracle.com>
Acked-by: Jeff Layton <jlayton@primarydata.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>