can: janz-ican3: drop invalid skbs

The commit which added the janz-ican3 driver and commit
3ccd4c61 "can: Unify droping of invalid tx skbs and netdev stats" were
committed into mainline Linux during the same merge window.

Therefore, the addition of this code to the janz-ican3 driver was
forgotten. This patch adds the expected code.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/janz-ican3.c b/drivers/net/can/janz-ican3.c
index f41623d..754b803 100644
--- a/drivers/net/can/janz-ican3.c
+++ b/drivers/net/can/janz-ican3.c
@@ -1420,6 +1420,9 @@
 	void __iomem *desc_addr;
 	unsigned long flags;
 
+	if (can_dropped_invalid_skb(ndev, skb))
+		return NETDEV_TX_OK;
+
 	spin_lock_irqsave(&mod->lock, flags);
 
 	/* check that we can actually transmit */