nfsd: clean up grace period on early exit

If nfsd was shut down before the grace period ended, we could end up
with a freed object still on grace_list.  Thanks to Jeff Moyer for
reporting the resulting list corruption warnings.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b0bebc5..1a052ac2 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3261,6 +3261,7 @@
 {
 	cancel_rearming_delayed_workqueue(laundry_wq, &laundromat_work);
 	destroy_workqueue(laundry_wq);
+	locks_end_grace(&nfsd4_manager);
 	nfs4_lock_state();
 	nfs4_release_reclaim();
 	__nfs4_state_shutdown();