patch 8.2.0996: using "aucmdwin" in win_gettype() is not ideal

Problem:    Using "aucmdwin" in win_gettype() is not ideal.
Solution:   Rename to "autocmd".
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index 285d994..e8f513a 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
@@ -2592,7 +2592,7 @@
   augroup END
 
   doautoall BufEnter
-  call assert_equal([['one.txt', 'aucmdwin'], ['two.txt', '']], g:blist)
+  call assert_equal([['one.txt', 'autocmd'], ['two.txt', '']], g:blist)
 
   augroup aucmd_win_test
     au!