patch 8.2.1432: various inconsistencies in test files

Problem:    Various inconsistencies in test files.
Solution:   Add modelines where they were missing.  Use Check commands instead
            of silently skipping over tests.  Adjust indents and comments.
            (Ken Takata, closes #6695)
diff --git a/src/testdir/test_lineending.vim b/src/testdir/test_lineending.vim
index d531b74..3f214e4 100644
--- a/src/testdir/test_lineending.vim
+++ b/src/testdir/test_lineending.vim
@@ -1,5 +1,6 @@
 " Tests for saving/loading a file with some lines ending in
 " CTRL-M, some not
+
 func Test_lineending()
   let l = ["this line ends in a\<CR>",
 	      \ "this one doesn't",
@@ -17,3 +18,5 @@
   new | only
   call delete('Xfile1')
 endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab