just spray your cabinet down with a water bottle and wipe out. Pollen usually is only viable for a week or 2, so it should be fine by your next grow, but just wipe it out as good as possible anyway.
I actually had it happen to me once. A hermie pollenante an entire cabinet of NL#5 x Haze. I was bummed because I was getting about 10 ounces of that harvest and instead I got hundreds of seeds.
Just give it a good spraying with a water bottle and wipe it up and you'll be ok