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>

include/linux/lockd/lockd.h

@@ -245,6 +245,7 @@ extern void	  nlm_host_rebooted(const struct sockaddr_in *, const char *,
  * Host monitoring
  */
 int		  nsm_monitor(const struct nlm_host *host);
+void		  nsm_unmonitor(const struct nlm_host *host);
 
 /*
  * This is used in garbage collection and resource reclaim

include/linux/lockd/sm_inter.h

@@ -41,7 +41,6 @@ struct nsm_res {
 	u32		state;
 };
 
-int		nsm_unmonitor(struct nlm_host *);
 extern int	nsm_local_state;
 
 #endif /* LINUX_LOCKD_SM_INTER_H */