Fix Uninstall-ChocolateyPackage not working for MSI

When you call Unstall-ChocolateyPackage, it would fail with a 1619 error. That's caused by Windows Installer not being locate the .msi. After looking at the helper a little, it turns out that the file path isn't being included in the arguments. This adds it back in, emulating Install-ChocolateyInstallPackage.