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_bufwintabinfo.vim b/src/testdir/test_bufwintabinfo.vim
index eafadff..f201753 100644
--- a/src/testdir/test_bufwintabinfo.vim
+++ b/src/testdir/test_bufwintabinfo.vim
@@ -1,4 +1,5 @@
 " Tests for the getbufinfo(), getwininfo() and gettabinfo() functions
+
 source check.vim
 
 func Test_getbufwintabinfo()
@@ -168,3 +169,5 @@
   edit Xfoo
   bw!
 endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab