batman-adv: fix lock class for decoding hash in network-coding.c

batman-adv: fix lock class for decoding hash in network-coding.c

batadv_has_set_lock_class() is called with the wrong hash table as first
argument (probably due to a copy-paste error), which leads to false
positives when running with lockdep.

Introduced-by: 2655d8806f9f986b7bd5e0978199bdf7de7dddfb
("batman-adv: network coding - save overheard and tx packets for decoding")

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>