can: mcp251x: fix NOHZ local_softirq_pending 08 warning

This patch replaces netif_rx() with netif_rx_ni() which has to be used
from the threaded interrupt i.e. process context context.

Thanks to Christian Pellegrin for pointing at the right fix:
481a8199 by Oliver Hartkopp.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>

drivers/net/can/mcp251x.c

@@ -451,7 +451,7 @@ static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
 
 	priv->net->stats.rx_packets++;
 	priv->net->stats.rx_bytes += frame->can_dlc;
-	netif_rx(skb);
+	netif_rx_ni(skb);
 }
 
 static void mcp251x_hw_sleep(struct spi_device *spi)
@@ -676,7 +676,7 @@ static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
 	if (skb) {
 		frame->can_id = can_id;
 		frame->data[1] = data1;
-		netif_rx(skb);
+		netif_rx_ni(skb);
 	} else {
 		dev_err(&net->dev,
 			"cannot allocate error skb\n");