can: rockchip: rkcanfd_handle_rx_fifo_overflow_int(): bail out if skb cannot be allocated

Fix NULL pointer check in rkcanfd_handle_rx_fifo_overflow_int() to
bail out if skb cannot be allocated.

Fixes: ff60bfb ("can: rockchip_canfd: add driver for Rockchip CAN-FD controller")
Cc: stable@vger.kernel.org
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Link: https://patch.msgid.link/20250208-fix-rockchip-canfd-v1-1-ec533c8a9895@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Author: rvdgracht

drivers/net/can/rockchip/rockchip_canfd-core.c

@@ -622,7 +622,7 @@ rkcanfd_handle_rx_fifo_overflow_int(struct rkcanfd_priv *priv)
 	netdev_dbg(priv->ndev, "RX-FIFO overflow\n");
 
 	skb = rkcanfd_alloc_can_err_skb(priv, &cf, &timestamp);
-	if (skb)
+	if (!skb)
 		return 0;
 
 	rkcanfd_get_berr_counter_corrected(priv, &bec);