Staging: batman-adv: Mark locally used symbols as static

Functions and variables which are used only inside one object file can
be declared as static. This helped to find unused functions/variables

 * mainIfAddr_default
 * main_if_was_up

and functions with declarations but missing definitions

 * hash_debug
 * orig_find
 * send_own_packet_work

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