Use os.Executable for daemon_darwin.go

[priyawadhwa]

Currently, we can't cross compile darwin on linux because it uses CGO. I think we could remove CGO entirely from that file and replace the current GetExecutablePath() function with:

func GetExecutablePath() (string, error) {
	return os.Executable()
}

If I'm missing something here please let me know, but I tested locally and it seems to be working. Happy to submit a PR if this is a suitable fix.