patch 8.1.0708: third argument for redrawWinline() is always FALSE

Problem:    Third argument for redrawWinline() is always FALSE.
Solution:   Drop the argument. (neovim #9479)
diff --git a/src/screen.c b/src/screen.c
index 04f19d7..880d784 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -492,28 +492,13 @@
     void
 redrawWinline(
     win_T	*wp,
-    linenr_T	lnum,
-    int		invalid UNUSED)	/* window line height is invalid now */
+    linenr_T	lnum)
 {
-#ifdef FEAT_FOLDING
-    int		i;
-#endif
-
     if (wp->w_redraw_top == 0 || wp->w_redraw_top > lnum)
 	wp->w_redraw_top = lnum;
     if (wp->w_redraw_bot == 0 || wp->w_redraw_bot < lnum)
 	wp->w_redraw_bot = lnum;
     redraw_win_later(wp, VALID);
-
-#ifdef FEAT_FOLDING
-    if (invalid)
-    {
-	/* A w_lines[] entry for this lnum has become invalid. */
-	i = find_wl_entry(wp, lnum);
-	if (i >= 0)
-	    wp->w_lines[i].wl_valid = FALSE;
-    }
-#endif
 }
 
     void