CVE-2025-38430

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

nfsd: nfsd4_spo_must_allow() must check this is a v4 compound request

If the request being processed is not a v4 compound request, then
examining the cstate can have undefined results.

This patch adds a check that the rpc procedure being executed
(rq_procinfo) is the NFSPROC4_COMPOUND procedure.