CVE-2026-52981 neigh: let neigh_xmit take skb ownership

In the Linux kernel, the following vulnerability has been resolved: neigh: let neighxmit take skb ownership neighxmit always releases the skb, except when no neighbour table is found. But even the first added user of neighxmit mpls relied on neighxmit to release the skb or queue it for tx. sashik...