xprtrdma: use complete() instead complete_all()

There is only one waiter for the completion, therefore there
is no need to use complete_all(). Let's make that clear by
using complete() instead of complete_all().

The usage pattern of the completion is:

waiter context                          waker context

frwr_op_unmap_sync()
  reinit_completion()
  ib_post_send()
  wait_for_completion()

					frwr_wc_localinv_wake()
					  complete()
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: linux-nfs@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/frwr_ops.c

@@ -330,7 +330,7 @@ frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc)
 	frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);
 	if (wc->status != IB_WC_SUCCESS)
 		__frwr_sendcompletion_flush(wc, frmr, "localinv");
-	complete_all(&frmr->fr_linv_done);
+	complete(&frmr->fr_linv_done);
 }
 
 /* Post a REG_MR Work Request to register a memory region