nfsd: Do not try to cache a reply for NFSERR_BADSLOT

When nfsrv_checksequence() replies NFSERR_BADSLOT,
the value of nd_slotid is not valid. As such, the
reply cannot be cached in the session.
Do not set ND_HASSEQUENCE for this case.

PR: 260076

(cherry picked from commit 33d0be8a923a840ec0724d50815890c5ffe0e884)