rxrpc: Record calls that need to be accepted

Record calls that need to be accepted using sk_acceptq_added() otherwise
the backlog counter goes negative because sk_acceptq_removed() is called.
This causes the preallocator to malfunction.

Calls that are preaccepted by AFS within the kernel aren't affected by
this.

Signed-off-by: David Howells <dhowells@redhat.com>

net/rxrpc/call_accept.c

@@ -369,6 +369,8 @@ found_service:
 
 	if (rx->notify_new_call)
 		rx->notify_new_call(&rx->sk, call, call->user_call_ID);
+	else
+		sk_acceptq_added(&rx->sk);
 
 	spin_lock(&conn->state_lock);
 	switch (conn->state) {