nfsd4: stop grace_time update at end of grace period

The attempt to automatically set a new grace period time at the end of
the grace period isn't really helpful.  We'll probably shut down and
reboot before we actually make use of the new grace period time anyway.
So may as well leave it up to the init system to get this right.

This just confuses people when they see /proc/fs/nfsd/nfsv4gracetime
change from what they set it to.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

@@ -4124,12 +4124,6 @@ nfsd4_end_grace(struct nfsd_net *nn)
 	nn->grace_ended = true;
 	nfsd4_record_grace_done(nn);
 	locks_end_grace(&nn->nfsd4_manager);
-	/*
-	 * Now that every NFSv4 client has had the chance to recover and
-	 * to see the (possibly new, possibly shorter) lease time, we
-	 * can safely set the next grace time to the current lease time:
-	 */
-	nn->nfsd4_grace = nn->nfsd4_lease;
 }
 
 static time_t