Use minimal logging when getting the VS install root from build.cmd

Author: kzu

build.cmd

@@ -59,7 +59,7 @@ if %MSBuildMajorVersion% LSS 15 (
 
 :: Ensure developer command prompt variables are set
 if "%VisualStudioVersion%" == "" (
-  for /f "delims=" %%i in ('msbuild build.props -nologo /t:GetVsInstallRoot') do set "VsInstallRoot=%%i" & goto :VsInstallRootDone
+  for /f "delims=" %%i in ('msbuild build.props /nologo /v:m /t:GetVsInstallRoot') do set "VsInstallRoot=%%i" & goto :VsInstallRootDone
 :VsInstallRootDone
   for /f "tokens=* delims= " %%i in ("%VsInstallRoot%") do set "VsInstallRoot=%%i"
   set "DeveloperCommandPrompt=%VsInstallRoot%\Common7\Tools\VsDevCmd.bat"