smb3: Fix root directory when server returns inode number of zero

Some servers return inode number zero for the root directory, which
causes ls to display incorrect data (missing "." and "..").

If the server returns zero for the inode number of the root directory,
fake an inode number for it.

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 3e3f868..2282562 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1470,6 +1470,7 @@ struct dfs_info3_param {
 #define CIFS_FATTR_NEED_REVAL		0x4
 #define CIFS_FATTR_INO_COLLISION	0x8
 #define CIFS_FATTR_UNKNOWN_NLINK	0x10
+#define CIFS_FATTR_FAKE_ROOT_INO	0x20
 
 struct cifs_fattr {
 	u32		cf_flags;