patch 9.1.1366: v9.1.1364 unintentionally changed sign.c and sound.c

Problem:  v9.1.1364 unintentionally changed sign.c and sound.c
Solution: revert those parts, adjust the test (Hirohito Higashi)

closes: #17264

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_codestyle.vim b/src/testdir/test_codestyle.vim
index 1d2717c..b7bbad3 100644
--- a/src/testdir/test_codestyle.vim
+++ b/src/testdir/test_codestyle.vim
@@ -166,6 +166,9 @@
 def Test_indent_of_source_files()
   for fname in glob('../*.[ch]', 0, 1) + ['../xxd/xxd.c']
     execute 'tabnew ' .. fname
+    if &expandtab
+      continue
+    endif
     for lnum in range(1, line('$'))
       var name: string = synIDattr(synID(lnum, 1, 0), 'name')
       if -1 == index(['cComment', 'cCommentStart'], name)
@@ -173,7 +176,7 @@
         var indent: string = matchstr(line, '^\s*')
         var tailing: string = matchstr(line, '\s*$')
         if !empty(indent)
-          if indent !~# '^\t* \{0,7\}$'
+          if indent !~# '^\t* \{0,7}$'
             ReportError('testdir/' .. fname, lnum, 'invalid indent')
           endif
         endif