Staging: batman-adv: Unify sysfs file names with their bat_priv atomics

Both sysfs entries and variable names shall be as descriptive as
possible while not exceeding a certain length. This patch renames
bat_priv atomics to be equally descriptive with their according sysfs
entries.

Unifying sysfs and bat_priv atomic names also makes it easier to find
each others pendant.

The reduced ("type"-)information which was previously indicated with a
_enabled for booleans got substituted by a comment in bat_priv.

This patch has also been done in regards for the future BAT_ATTR_*
macros (they only need one name argument instead of a file and variable
name).

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
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>