[Bug] Fix for the build_windows.bat file

[no-realm]

Hey,

I noticed that when you try to execute make driver_load on a different drive than C on Windows, it complains about LaunchBuildEnv.cmd not being a valid command/file.
To fix this, I had to change the cd commands to include /D, which forces a drive change.
From the cd documentation:

Use the /D switch to change current drive in addition to changing current
directory for a drive.

In short:
cd C:\ewdk\ -> cd /D C:\ewdk\.
cd %1 -> cd /D %1

[rianquinn]

Thanks a ton for the bug report. Would you like to post a PR for this change?

[no-realm]

Sure, I will do that in a moment.