patch 9.0.1257: code style is not check in test scripts

Problem:    Code style is not check in test scripts.
Solution:   Add basic code style check for test files.
diff --git a/src/testdir/test_visual.vim b/src/testdir/test_visual.vim
index df781a0..a56c288 100644
--- a/src/testdir/test_visual.vim
+++ b/src/testdir/test_visual.vim
@@ -1167,8 +1167,8 @@
 func Test_visual_put_in_block_using_zp()
   new
   " paste using zP
-  call setline(1, ['/path;text', '/path;text', '/path;text', '', 
-    \ '/subdir', 
+  call setline(1, ['/path;text', '/path;text', '/path;text', '',
+    \ '/subdir',
     \ '/longsubdir',
     \ '/longlongsubdir'])
   exe "normal! 5G\<c-v>2j$y"
@@ -1176,8 +1176,8 @@
   call assert_equal(['/path/subdir;text', '/path/longsubdir;text', '/path/longlongsubdir;text'], getline(1, 3))
   %d
   " paste using zP
-  call setline(1, ['/path;text', '/path;text', '/path;text', '', 
-    \ '/subdir', 
+  call setline(1, ['/path;text', '/path;text', '/path;text', '',
+    \ '/subdir',
     \ '/longsubdir',
     \ '/longlongsubdir'])
   exe "normal! 5G\<c-v>2j$y"
@@ -1190,7 +1190,7 @@
   new
 
   " Test 1) Paste using zp - after the cursor without trailing spaces
-  call setline(1, ['/path;text', '/path;text', '/path;text', '', 
+  call setline(1, ['/path;text', '/path;text', '/path;text', '',
     \ 'texttext  /subdir           columntext',
 		\ 'texttext  /longsubdir       columntext',
     \ 'texttext  /longlongsubdir   columntext'])
@@ -1200,7 +1200,7 @@
 
   " Test 2) Paste using zP - in front of the cursor without trailing spaces
   %d
-  call setline(1, ['/path;text', '/path;text', '/path;text', '', 
+  call setline(1, ['/path;text', '/path;text', '/path;text', '',
     \ 'texttext  /subdir           columntext',
 		\ 'texttext  /longsubdir       columntext',
     \ 'texttext  /longlongsubdir   columntext'])
@@ -1210,7 +1210,7 @@
 
   " Test 3) Paste using p - with trailing spaces
   %d
-  call setline(1, ['/path;text', '/path;text', '/path;text', '', 
+  call setline(1, ['/path;text', '/path;text', '/path;text', '',
     \ 'texttext  /subdir           columntext',
 		\ 'texttext  /longsubdir       columntext',
     \ 'texttext  /longlongsubdir   columntext'])
@@ -1220,7 +1220,7 @@
 
   " Test 4) Paste using P - with trailing spaces
   %d
-  call setline(1, ['/path;text', '/path;text', '/path;text', '', 
+  call setline(1, ['/path;text', '/path;text', '/path;text', '',
     \ 'texttext  /subdir           columntext',
 		\ 'texttext  /longsubdir       columntext',
     \ 'texttext  /longlongsubdir   columntext'])
@@ -1230,7 +1230,7 @@
 
   " Test 5) Yank with spaces inside the block
   %d
-  call setline(1, ['/path;text', '/path;text', '/path;text', '', 
+  call setline(1, ['/path;text', '/path;text', '/path;text', '',
     \ 'texttext  /sub    dir/           columntext',
     \ 'texttext  /lon    gsubdir/       columntext',
     \ 'texttext  /lon    glongsubdir/   columntext'])