While I actually think the name Errol is kinda neat (and it has already a nice "tolkenian" quality to it), my Latin sense is tingling here, as I don't think there is a derivation from "erro, -onis" (vagabond, wanderer) to Errol. From a linguistic point of view, it doesn't really make sense. I did a bit of searching, and most sources say it's either a variant of "Earl" (warrior, nobleman: from proto-Germanic "erlaz"), or a Scottish surname derived from a place (Errol). A few say it's from Latin, but while I'm not an expert in etymology, it doesn't sound true. Sorry to be pedantic, but if you want a tattoo with that, better to be safe than sorry.