patch 9.0.0828: various typos

Problem:    Various typos.
Solution:   Correct typos. (closes #11432)
diff --git a/src/testdir/test_fold.vim b/src/testdir/test_fold.vim
index 9b8cd73..e22ede9 100644
--- a/src/testdir/test_fold.vim
+++ b/src/testdir/test_fold.vim
@@ -1342,7 +1342,7 @@
 
 " Test for merging two recursive folds when an intermediate line with no fold
 " is removed
-func Test_fold_merge_recrusive()
+func Test_fold_merge_recursive()
   new
   call setline(1, ['  one', '    two', 'xxxx', '    three',
         \ '      four', "\tfive"])