Trading the first Totem ability for a fighting style seems fair. Hell, make up an entire totem animal (Lion or Monkey or Mantis Shrimp or something) oriented around two-weapon fighting to bring this build up to par.
Totem of the Wyrm
At 3rd level, a Dragonborn barbarian develops a tail which he can use as his second weapon attack
Also gives Advantage to any dex check for climbing or falling.