batman-adv: code refactoring - move debug print into tt_local_set_pending

Each tt_local_set_pending is always followed by a bat_dbg invocation. This can
be simplified by moving the bat_dbg() call.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>