sfc: fix null pointer dereference in efx_hard_start_xmit
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.15.71 by commit 8547c7bfc0617e7184e4da65b9b96681fcfe9998, it was introduced in version v5.10 by commit 12804793b17c0e19115a90d98f2f3df0cb79e233. For more details please see the references link.