Use proper arg key for --help option

Running `lpmake --help` leads to a segfault. It happens because invalid key is used for --help option.

Test: build lpmake and make sure --help works
Issue: https://github.com/nmeum/android-tools/issues/73
Change-Id: I8a2c56b6f2c9dc0a3f254e85469ce10d09c02bc7
1 file changed