SUNRPC: remove dead variable 'rpciod_running'

rpciod_running is not used at all, but due to the way DECLARE_MUTEX_LOCKED
works we don't get a warning for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/sched.c

@@ -989,8 +989,6 @@ void rpc_killall_tasks(struct rpc_clnt *clnt)
 	spin_unlock(&rpc_sched_lock);
 }
 
-static DECLARE_MUTEX_LOCKED(rpciod_running);
-
 static void rpciod_killall(void)
 {
 	unsigned long flags;