nfsd: recovery - make in_grace per net

Flag in_grace is a part of client tracking state, which is network namesapce
aware. So let'a replace global static variable with per-net one.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 1305632..9047706 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -86,6 +86,7 @@
 	spinlock_t client_lock;
 
 	struct file *rec_file;
+	bool in_grace;
 };
 
 extern int nfsd_net_id;