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_quotestar.vim b/src/testdir/test_quotestar.vim
index 9386586..9e04e19 100644
--- a/src/testdir/test_quotestar.vim
+++ b/src/testdir/test_quotestar.vim
@@ -36,7 +36,7 @@
 
   let cmd = GetVimCommand()
   if cmd == ''
-    return 'GetVimCommand() failed'
+    throw 'GetVimCommand() failed'
   endif
   try
     call remote_send('xxx', '')
@@ -152,3 +152,5 @@
     throw 'Skipped: ' . skipped
   endif
 endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab