[MacOS] Potential issues reported by clang (low to medium priority)

[k1-801]

Clang produces the following warnings:

It might be a good idea to address them to avoid seemingly random crashes.

Additionally, the kernel error returned in HID device path generation code seems to remain ignored, and if the path fails to generate, it will still proceed to create the structure, even though the device will not be able to be opened. Might be worth looking into.