nfc: pn533: purge fragmented skbs during cleanup

commit 5718fc6 upstream.

pn53x_common_clean() purges resp_q before freeing the common PN533 state,
but it leaves fragment_skb untouched.  The fragmentation helpers queue
transmit fragments there while sending large initiator or target-mode
frames, and those skbs remain owned by the driver until they are sent or
discarded.

If the device is removed while fragments are still queued, the common
cleanup path frees the PN533 state without releasing the queued fragment
skbs, leaking them.

Purge fragment_skb during cleanup alongside resp_q.

Fixes: 963a82e ("NFC: pn533: Split large Tx frames in chunks")
Cc: stable@vger.kernel.org
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Link: https://patch.msgid.link/2D896607CAE4408E+20260720021444.3362044-1-raoxu@uniontech.com
Signed-off-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Xu Rao

drivers/nfc/pn533/pn533.c

@@ -2803,6 +2803,7 @@ void pn53x_common_clean(struct pn533 *priv)
 	destroy_workqueue(priv->wq);
 
 	skb_queue_purge(&priv->resp_q);
+	skb_queue_purge(&priv->fragment_skb);
 
 	list_for_each_entry_safe(cmd, n, &priv->cmd_queue, queue) {
 		list_del(&cmd->queue);