Does a college campus address count as residency in a state if I put it as my address on my W4 in that state, but my home address is in a different state?

As a student attending college out-of-state, you are considered to remain a resident of (i.e. "live in") your home state unless you take action to establish residency in another state (does not have to be the state where you go to college). 

You can put whatever address you want on a W-4, but that doesn't change your state of residency.

See "What makes you a resident of a state (or country)?" at the bottom.

When you complete the Personal Interview:

1. Select "Your home state" as the state of residence on December 31, 2016;
2. Answer "No" when asked if you "Lived in another state in 2016?" That question only applies if you changed your state of residence in 2016.
3. Answer "No" when asked if you "Earned money in another state?", unless you earned money in a state other than your home state..

What makes you a resident of a state (or country)?  

Generally, you're a resident of a state (or country) if you intend to either stay there permanently, or return there after a temporary absence. It's where home is – where you come back to after being away on vacation, business trip, overseas or out-of-state employment, or school. Many factors are considered, not the least of which are where you are registered to vote, own homestead property and are licensed to drive.