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_fixeol.vim b/src/testdir/test_fixeol.vim
index 32cb059..e97bf00 100644
--- a/src/testdir/test_fixeol.vim
+++ b/src/testdir/test_fixeol.vim
@@ -1,4 +1,5 @@
 " Tests for 'fixeol' and 'eol'
+
 func Test_fixeol()
   " first write two test files – with and without trailing EOL
   " use Unix fileformat for consistency
@@ -46,3 +47,5 @@
   set ff& fixeol& eol&
   enew!
 endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab