NLM: Move the public declaration of nsm_unmonitor() to lockd.h

Clean up.

Make the nlm_host argument "const," and move the public declaration to
lockd.h.  Add a documenting comment.

Bruce observed that nsm_unmonitor()'s only caller doesn't care about
its return code, so make nsm_unmonitor() return void.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 15fab22..d61cdc6 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -107,15 +107,19 @@
 	return status;
 }
 
-/*
- * Cease to monitor remote host
+/**
+ * nsm_unmonitor - Unregister peer notification
+ * @host: pointer to nlm_host of peer to stop monitoring
+ *
+ * If this peer is monitored, this function sends an upcall to
+ * tell the local rpc.statd not to send this peer a notification
+ * when we reboot.
  */
-int
-nsm_unmonitor(struct nlm_host *host)
+void nsm_unmonitor(const struct nlm_host *host)
 {
 	struct nsm_handle *nsm = host->h_nsmhandle;
 	struct nsm_res	res;
-	int		status = 0;
+	int status;
 
 	if (atomic_read(&nsm->sm_count) == 1
 	 && nsm->sm_monitored && !nsm->sm_sticky) {
@@ -128,7 +132,6 @@
 		else
 			nsm->sm_monitored = 0;
 	}
-	return status;
 }
 
 /*