RDMA/siw: Remove set but not used variables 'rv'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/infiniband/sw/siw/siw_cm.c: In function siw_cep_set_inuse:
drivers/infiniband/sw/siw/siw_cm.c:223:6: warning: variable rv set but not used [-Wunused-but-set-variable]

Fixes: 6c52fdc ("rdma/siw: connection management")
Link: https://lore.kernel.org/r/20190719012938.100628-1-maowenan@huawei.com
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/sw/siw/siw_cm.c

@@ -220,13 +220,12 @@ static void siw_put_work(struct siw_cm_work *work)
 static void siw_cep_set_inuse(struct siw_cep *cep)
 {
 	unsigned long flags;
-	int rv;
 retry:
 	spin_lock_irqsave(&cep->lock, flags);
 
 	if (cep->in_use) {
 		spin_unlock_irqrestore(&cep->lock, flags);
-		rv = wait_event_interruptible(cep->waitq, !cep->in_use);
+		wait_event_interruptible(cep->waitq, !cep->in_use);
 		if (signal_pending(current))
 			flush_signals(current);
 		goto retry;