Considering the fact that you're playing a barbarian... it won't be a problem...
Here's why: You need a lot and I mean A LOT of feats to qualify for WM. Getting all those feat under your belt with a Barbarian will take tons of time anyway. So you'll probably have the ability points before the feats. So start taking your feats (dodge,mobility,spring attack, weapon focus, whirlwind attack) and save Expertise for when you have the 13 INT.
I doubt you'll make weaponmaster before epic without a fighter multiclass... but the INT part isn't such a bad thing. You'll manage.
EDIT: I hope your DEX is 13+ or no WM for you!
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