patch 8.2.3441: MS-Windows: vimtutor can't handle path with spaces

Problem:    MS-Windows: vimtutor can't handle path with spaces.
Solution:   Add double quotes. (Christian Brabandt, closes #8871)
diff --git a/vimtutor.bat b/vimtutor.bat
index 0387e98..da0940a 100644
--- a/vimtutor.bat
+++ b/vimtutor.bat
@@ -11,7 +11,7 @@
 
 :: Use Vim to copy the tutor, it knows the value of $VIMRUNTIME
 FOR %%d in (. %TMP% %TEMP%) DO (
-    call :test_dir_writable %~dpf0 %%d
+    call :test_dir_writable "%~dpf0" %%d
     IF NOT ERRORLEVEL 1 GOTO dir_ok
 )