can: rx-offload: can_rx_offload_offload_one(): do not increase the skb_queue...

can: rx-offload: can_rx_offload_offload_one(): do not increase the skb_queue beyond skb_queue_len_max

The skb_queue is a linked list, holding the skb to be processed in the
next NAPI call.

Without this patch, the queue length in can_rx_offload_offload_one() is
limited to skb_queue_len_max + 1. As the skb_queue is a linked list, no
array or other resources are accessed out-of-bound, however this
behaviour is counterintuitive.

This patch limits the rx-offload skb_queue length to skb_queue_len_max.

Fixes: d254586c ("can: rx-offload: Add support for HW fifo based irq offloading")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>