I get this question every now and again. I guess the answer is however you want to.
Personally I say it like "Lynn-ucks" which is like the person's name (Lynn) and the second half rhymes with "ducks." Like the kind that some people hunt and eat for dinner.
However, I think that only one person can provide the definitive answer and that would be to ask Linus Torvalds how HE says it. After all, who better to ask than the guy that initiated development of the Linux kernel?
Attached is a voice recording of how he says it. Sounds to me more like Leenex sort of like Kleenex. Hard to say for sure!