net: mvpp2: set SKBTX_IN_PROGRESS

Richard Cochran points out that SKBTX_IN_PROGRESS should be set when
the skbuff is queued for timestamping.  Add this.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -3701,6 +3701,8 @@ static bool mvpp2_tx_hw_tstamp(struct mvpp2_port *port,
 	if (!hdr)
 		return false;
 
+	skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+
 	ptpdesc = MVPP22_PTP_MACTIMESTAMPINGEN |
 		  MVPP22_PTP_ACTION_CAPTURE;
 	queue = &port->tx_hwtstamp_queue[0];