patch 8.0.1122: vimtutor.bat doesn't work well with vim.bat

Problem:    vimtutor.bat doesn't work well with vim.bat.
Solution:   Use "call vim". (Ken Takata, closes #2105)

Author: brammool

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1122,
 /**/
     1121,
 /**/

vimtutor.bat

@@ -47,11 +47,11 @@ GOTO end
 
 :use_vim
 :: The script tutor.vim tells Vim which file to copy
-vim -u NONE -c "so $VIMRUNTIME/tutor/tutor.vim"
+call vim -u NONE -c "so $VIMRUNTIME/tutor/tutor.vim"
 IF ERRORLEVEL 1 GOTO no_executable
 
 :: Start vim without any .vimrc, set 'nocompatible'
-vim -u NONE -c "set nocp" %TUTORCOPY%
+call vim -u NONE -c "set nocp" %TUTORCOPY%
 
 GOTO end