In a literal sense, "does fightingevil make you good" the answer is no, because of the obvious answer of "evil people fight other evil people all the time".
However, I think another way to look at the question is that assuming a PC is "Not Evil", does fighting evil make you good. How about, does not fighting evil make you good?
peaceful nuns helping sick people pretty much nail the "don't fight anything, still good" category.
I might put it this way, if you do NOT fight evil, when confronted by it, are you good or are you neutral?
Victims of crime who didn't resist, are they good or neutral?
Citizens of a town that is terrorized by armed criminals, if the citizens don't fight, are they good or neutral?
If someone tries to rob you, and you fight back, are you good? Or just protecting your property (neutral)?
I think, that if confronted by evil and you do nothing, not because doing something at that time is tactically inadvisable, but because, you just want to mind your own business, and hope they'll leave you alone, you are Neutral. At some point, a Good person makes a stand, takes a chance, because it will help himself, and help others. Maybe doing something means reporting to the police, sneaking supplies in or information out, or actually fighting.
The man who regretted he only had one life to give for his country was Good. The man who did nothing when they came for the Jews, was Neutral. And we all know what happened to him.