[R-package] Fix build_r.R failing in Windows (#1694)
[R-package] Fix build_r.R failing in Windows (#1694)

* Fix #1693

* Fix spacing

* Fr -> For

* Recursive causes error on strict R environments

microsoft/LightGBM,henry0312/LightGBM,microsoft/LightGBM,microsoft/LightGBM,henry0312/LightGBM,henry0312/LightGBM,microsoft/LightGBM,microsoft/LightGBM,henry0312/LightGBM,henry0312/LightGBM