BugLink: http://bugs.launchpad.net/bugs/1692900

commit d8a6e505 upstream.

An open directory may have a NULL private_data pointer prior to readdir.

Fixes: 0de1f4c6 ("Add way to query server fs info for smb3")
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>