net/9p: fix error path of p9_virtio_probe

[ Upstream commit 92aef4675d5b1b55404e1532379e343bed0e5cf2 ]

Currently when virtio_find_single_vq fails, we go through del_vqs which
throws a warning (Trying to free already-free IRQ).  Skip del_vqs if vq
allocation failed.

Link: http://lkml.kernel.org/r/20180524101021.49880-1-jean-philippe.brucker@arm.com
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index da0d3b2..e73fd64 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -571,7 +571,7 @@
 	chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
 	if (IS_ERR(chan->vq)) {
 		err = PTR_ERR(chan->vq);
-		goto out_free_vq;
+		goto out_free_chan;
 	}
 	chan->vq->vdev->priv = chan;
 	spin_lock_init(&chan->lock);
@@ -624,6 +624,7 @@
 	kfree(tag);
 out_free_vq:
 	vdev->config->del_vqs(vdev);
+out_free_chan:
 	kfree(chan);
 fail:
 	return err;