SUNRPC: get rid of the request wait queue

We're always _only_ waking up tasks from within the sp_threads list, so
we know that they are enqueued and alive. The rq_wait waitqueue is just
a distraction with extra atomic semantics.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

include/linux/sunrpc/svc.h

@@ -280,7 +280,6 @@ struct svc_rqst {
 	bool			rq_splice_ok;   /* turned off in gss privacy
 						 * to prevent encrypting page
 						 * cache pages */
-	wait_queue_head_t	rq_wait;	/* synchronization */
 	struct task_struct	*rq_task;	/* service thread */
 };