Reset TreeId to zero on SMB2 TREE_CONNECT

commit 806a28ef upstream.

Currently the cifs module breaks the CIFS specs on reconnect as
described in http://msdn.microsoft.com/en-us/library/cc246529.aspx

:

"TreeId (4 bytes): Uniquely identifies the tree connect for the
command. This MUST be 0 for the SMB2 TREE_CONNECT Request."

Signed-off-by: Jan-Marek Glogowski <glogow@fbihome.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Tested-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>