patch 9.0.2095: statusline may look different than expected

Problem:  statusline may look different than expected
Solution: do not check for highlighting of stl and stlnc characters

statusline fillchar may be different than expected

If the highlighting group for the statusline for the current window
|hl-StatusLine| or the non-current window |hl-StatusLineNC| are cleared
(or do not differ from each other), than Vim will use the hard-coded
fallback values '^' (for the non-current windows) or '=' (for the
current window).  I believe this was done, to make sure the statusline
will always be visible and be distinguishable from the rest of the
window.

However, this may be unexpected, if a user explicitly defined those
fillchar characters just to notice that those values are then not used
by Vim.

So, let's assume users know what they are doing and just always return
the configured stl and stlnc values.  And if they want the statusline to
be non-distinguishable from the rest of the window space, so be it.  It
is their responsibility and Vim shall not know better what to use.

fixes: #13366
closes: #13488

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/screen.c b/src/screen.c
index 3d931ab..fd69cf0 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -4462,16 +4462,7 @@
 	*attr = HL_ATTR(HLF_SNC);
 	fill = wp->w_fill_chars.stlnc;
     }
-    // Use fill when there is highlighting, and highlighting of current
-    // window differs, or the fillchars differ, or this is not the
-    // current window
-    if (*attr != 0 && ((HL_ATTR(HLF_S) != HL_ATTR(HLF_SNC)
-			|| wp != curwin || ONE_WINDOW)
-		    || (wp->w_fill_chars.stl != wp->w_fill_chars.stlnc)))
-	return fill;
-    if (wp == curwin)
-	return '^';
-    return '=';
+    return fill;
 }
 
 /*