sfc: fix null pointer dereference in efxhardstart_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 v6.0 by commit 0a242eb2913a4aa3d6fbdb86559f27628e9466f3, it was introduced in version v5.10 by commit 12804793b17c0e19115a90d98f2f3df0cb79e233. For more details please see the references link.