statd: Replace nsm_log() with xlog() in sm-notify command

To facilitate code sharing between statd and sm-notify (and with other
components of nfs-utils), replace sm-notify's nsm_log() with xlog().

Since opt_quiet is used in only a handful of insignificant cases, it
is removed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>