9p: client: remove unused code and any reference to "cancelled" function

This patch reverts commit

80b45261a0b263536b043c5ccfc4ba4fc27c2acc

which was implementing a 'cancelled' functionality to notify that
a cancelled request will not be replied.

This implementation was not used anywhere and therefore removed.

Signed-off-by: Andi Shyti <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/9p/transport.h

···
  * @close: member function to discard a connection on this transport
  * @request: member function to issue a request to the transport
  * @cancel: member function to cancel a request (if it hasn't been sent)
- * @cancelled: member function to notify that a cancelled request will not
- *             not receive a reply
  *
  * This is the basic API for a transport module which is registered by the
  * transport module with the 9P core network module and used by the client
···
 	void (*close) (struct p9_client *);
 	int (*request) (struct p9_client *, struct p9_req_t *req);
 	int (*cancel) (struct p9_client *, struct p9_req_t *req);
-	int (*cancelled)(struct p9_client *, struct p9_req_t *req);
 	int (*zc_request)(struct p9_client *, struct p9_req_t *,
 			  char *, char *, int , int, int, int);
 };

net/9p/client.c

···
 
 	/*
 	 * if we haven't received a response for oldreq,
-	 * remove it from the list, and notify the transport
-	 * layer that the reply will never arrive.
+	 * remove it from the list
 	 */
-	spin_lock(&c->lock);
 	if (oldreq->status == REQ_STATUS_FLSH) {
+		spin_lock(&c->lock);
 		list_del(&oldreq->req_list);
-		spin_unlock(&c->lock);
-		if (c->trans_mod->cancelled)
-			c->trans_mod->cancelled(c, req);
-	} else {
 		spin_unlock(&c->lock);
 	}