bnxt_en: Restore PTP tx_avail count in case of skb_pad() error

The current code only restores PTP tx_avail count when we get DMA
mapping errors.  Fix it so that the PTP tx_avail count will be
restored for both DMA mapping errors and skb_pad() errors.
Otherwise PTP TX timestamp will not be available after a PTP
packet hits the skb_pad() error.

Fixes: 83bb623 ("bnxt_en: Transmit and retrieve packet timestamps")
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240618215313.29631-4-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -732,9 +732,6 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	return NETDEV_TX_OK;
 
 tx_dma_error:
-	if (BNXT_TX_PTP_IS_SET(lflags))
-		atomic_inc(&bp->ptp_cfg->tx_avail);
-
 	last_frag = i;
 
 	/* start back at beginning and unmap skb */
@@ -756,6 +753,8 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 tx_free:
 	dev_kfree_skb_any(skb);
 tx_kick_pending:
+	if (BNXT_TX_PTP_IS_SET(lflags))
+		atomic_inc(&bp->ptp_cfg->tx_avail);
 	if (txr->kick_pending)
 		bnxt_txr_db_kick(bp, txr, txr->tx_prod);
 	txr->tx_buf_ring[txr->tx_prod].skb = NULL;