CVE-2026-99046: gve: fix XSK buffer leak on error descriptor

In the Linux kernel, the following vulnerability has been resolved:

gve: fix XSK buffer leak on error descriptor

When the error bit is set in the RX completion descriptor, the bufstate and its attached buffer should be freed. In the case of AFXDP ZC, the XSK buffer was not freed, leading to a leak.

This issue was caught by LLM.