Add support for errors in hid_error on MacOS

[hardkrash]

The IOreturn value can be passed to the c library function mach_error_string to provide the error string for the error that was raised.

mach_error_string is defined in mach_error.h

char *mach_error_string(mach_error_t error_value); and a IOReturn is a version of mach_error_t

[mcuee]

@hardkrash Please help to create a pull request. Thanks.

[Youw]

Oh, this is done as part of https://github.com/libusb/hidapi/pull/314. Available in the latest release.