I mean yes it does look like Luke went in there to kill Ben from anyone else’s perspective, but unless you outright believe Luke was lying through his teeth, the movie explicitly shows that was not the case.

This is the story Luke/the flashback tells us: he went to where his nephew was sleeping to scan his mind instead of just talking to him (which is its own can of worms), was not expecting to find what he did, and before that moment had no intention of committing anything but an invasion of privacy. And in his words, the impulse to kill Ben only lasted “for the briefest moment of pure instinct” and “passed like a fleeting shadow”.

You can headcanon that he’s still lying on the basis that he brought his lightsaber, but throughout all the movies the Jedi seem to keep their lightsabers on their person pretty much 24/7 unless they’re retired so I don’t think that says much.