I think you are mistaken. At least from my reading of The Stranger I remember Camus stating suicide is a cowardly act. Wikipedia[1] states Camus viewed suicide as a rejection of freedom. Also the myth of sisyphus doesn't have much to do with suicide does it? I may be mistaken. I thought it was more of an analogy to the condition of man, not so much a suggestion to commit suicide to avoid it.
[1] https://en.wikipedia.org/wiki/Philosophy_of_suicide#Absurdis...