fix(windows build): Use correct variable to specify target architecture when calling vcvarsall.bat (#8765)

Co-authored-by: Artyom Ivanov <artyom.ivanov@red-soft.ru>

Author: TreeHunter9

builds/win32/setenvvar.bat

@@ -83,10 +83,10 @@
 :: Run vsvarsall just once during the build...
 @if DEFINED FB_VSCOMNTOOLS (
  @if not defined VCToolsVersion (
- call "%FB_VSCOMNTOOLS%\..\..\VC\Auxiliary\Build\vcvarsall.bat" %PROCESSOR_ARCHITECTURE%
+ call "%FB_VSCOMNTOOLS%\..\..\VC\Auxiliary\Build\vcvarsall.bat" %FB_PROCESSOR_ARCHITECTURE%
  ) else (
  @echo The file:
- @echo "%FB_VSCOMNTOOLS%\..\..\VC\Auxiliary\Build\vcvarsall.bat" %PROCESSOR_ARCHITECTURE%
+ @echo "%FB_VSCOMNTOOLS%\..\..\VC\Auxiliary\Build\vcvarsall.bat" %FB_PROCESSOR_ARCHITECTURE%
  @echo has already been executed.
  )
 )