nfsd4: set sequence flag when backchannel is down

Implement the SEQ4_STATUS_CB_PATH_DOWN flag.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 3a7aa4d..366401e 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -378,8 +378,8 @@
 	u32			cachethis;		/* request */
 #if 0
 	u32			target_maxslots;	/* response */
-	u32			status_flags;		/* response */
 #endif /* not yet */
+	u32			status_flags;		/* response */
 };
 
 struct nfsd4_destroy_session {