Staging: batman-adv: fix early debugfs deinitialization

The debugfs files are initialized at load time only but would get
deinitialized when the module changed in it deactivate (sleeping)
state. As a consequence the debugfs files are not accessible
anymore.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>