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_fnameescape.vim b/src/testdir/test_fnameescape.vim
index cdb96ba..e24d64d 100644
--- a/src/testdir/test_fnameescape.vim
+++ b/src/testdir/test_fnameescape.vim
@@ -1,5 +1,5 @@
-
 " Test if fnameescape is correct for special chars like !
+
 func Test_fnameescape()
   let fname = 'Xspa ce'
   let status = v:false