message: samples(run_python): fix registry values querying
diff: @@ -30,12 +30,13 @@ GOTO :PYTHON_NOT_FOUND
  :QUERY_PYTHON
  SETLOCAL
  SET PY_VERSION=%1
  -FOR /F "tokens=2*" %%A IN ('REG QUERY "HKCU\SOFTWARE\Python\PythonCore\%PY_VERSION%\InstallPath" /reg:64 /ve 2^>NUL ^| FIND "REG_SZ"') DO SET PYTHON_DIR=%%B
  +SET PYTHON_DIR=
  +CALL :regquery "HKCU\SOFTWARE\Python\PythonCore\%PY_VERSION%\InstallPath" PYTHON_DIR
  IF EXIST "%PYTHON_DIR%\python.exe" (
  SET "PYTHON=%PYTHON_DIR%\python.exe"
  GOTO :QUERY_PYTHON_FOUND
  )
  -FOR /F "tokens=2*" %%A IN ('REG QUERY "HKLM\SOFTWARE\Python\PythonCore\%PY_VERSION%\InstallPath" /reg:64 /ve 2^>NUL ^| FIND "REG_SZ"') DO SET PYTHON_DIR=%%B
  +CALL :regquery "HKLM\SOFTWARE\Python\PythonCore\%PY_VERSION%\InstallPath" PYTHON_DIR
  IF EXIST "%PYTHON_DIR%\python.exe" (
  SET "PYTHON=%PYTHON_DIR%\python.exe"
  GOTO :QUERY_PYTHON_FOUND
  @@ -46,7 +47,7 @@ ENDLOCAL
  EXIT /B 1
  :QUERY_PYTHON_FOUND
  -ECHO Found Python %PY_VERSION% from Windows Registry
  +ECHO Found Python %PY_VERSION% from Windows Registry: %PYTHON%
  ENDLOCAL & SET PYTHON=%PYTHON%
  EXIT /B 0
  @@ -112,3 +113,12 @@ EXIT /B %result%
  set _dir=%_dir:~0,-1%
  endlocal & set %2=%_dir%
  EXIT /B 0
  +
  +:regquery name resultVar
  + SETLOCAL
  + FOR /F "tokens=*" %%A IN ('REG QUERY "%1" /reg:64 /ve 2^>NUL ^| FIND "REG_SZ"') DO SET _val=%%A
  + IF "x%_val%x"=="xx" EXIT /B 1
  + SET _val=%_val:*REG_SZ=%
  + FOR /F "tokens=*" %%A IN ("%_val%") DO SET _val=%%A
  + ENDLOCAL & SET %2=%_val%
  + EXIT /B 0
  