nfc: st-nci: Remove data from ack_pending_q when receiving a SYNC_ACK

When receiving a NDLC PCB_SYNC_ACK the pending data was never
removed from ack_pending_q and cleared.

Cc: stable@vger.kernel.org
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/st-nci/ndlc.c

@@ -171,6 +171,8 @@ static void llt_ndlc_rcv_queue(struct llt_ndlc *ndlc)
 		if ((pcb & PCB_TYPE_MASK) == PCB_TYPE_SUPERVISOR) {
 			switch (pcb & PCB_SYNC_MASK) {
 			case PCB_SYNC_ACK:
+				skb = skb_dequeue(&ndlc->ack_pending_q);
+				kfree_skb(skb);
 				del_timer_sync(&ndlc->t1_timer);
 				del_timer_sync(&ndlc->t2_timer);
 				ndlc->t2_active = false;