Fix bug in Unicode colloation that causes ASSERT on BeagleBoard. PlatformLang or...

Fix bug in Unicode colloation that causes ASSERT on BeagleBoard. PlatformLang or Lang variables are not processed correctly. NULL pointer is passed if no variable exists.

(based on FatPkg commit 0e3c94b9ac164caf705cc512a0e865fa0811b531)

[jordan.l.justen@intel.com: Use script to relicense to 2-clause BSD]
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Andrew Fish <afish@apple.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>