fixed error detection & reporting on wineprefix creation failure

[LeXofLeviafan]

Currently the prefix creation failure is ignored, and consequently leads to an error at a later step (typically a generic "unhandled error" message).

Adding a check and showing contextual error message (as well as logging the error) makes it easier to figure out what went wrong (…e.g. that the wine executable is not in current $PATH :sweat_smile:).

[sharkwouter]

Thanks! That's a good addition!

[sharkwouter]

Thanks! Sorry about forgetting about this for a while. I had some stuff going on in my personal life. The contribution is really appreciated!