nfsd4: fix exchange_id to return confirm flag

Otherwise nfsd4_set_ex_flags writes over the return flags.

Reported-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e4d9b56..83a6898 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1617,7 +1617,7 @@
 			goto expire_client;
 		}
 		if (verfs_match) { /* case 2 */
-			exid->flags |= EXCHGID4_FLAG_CONFIRMED_R;
+			conf->cl_exchange_flags |= EXCHGID4_FLAG_CONFIRMED_R;
 			new = conf;
 			goto out_copy;
 		}