I'm reluctant to reply here because you're not asking a good question. You're asking someone else to make a life choice for you.
Both fields are very similar. Both use their skills very similarly. However Mechatronics engineers tend to see their results doing physical things, whereas Computer Scientists tend to see their devices doing Interesting abstract things.
People try to predict job markets and they frequently get it horribly wrong. I think these two choices are so intertwined that whatever happens to one is likely to have very significant effects upon the other. If someone responds with a quantitative result to your question you should not take them seriously.
Choose what amuses you and pursue that. Good luck!