patch 9.0.0206: redraw flags are not named specifically

Problem:    Redraw flags are not named specifically.
Solution:   Prefix "UPD_" to the flags, for UPDate_screen().
diff --git a/src/misc1.c b/src/misc1.c
index f4a313d..6b01ef2 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -585,8 +585,8 @@
 	if (wp->w_buffer == buf && wp->w_status_height)
 	{
 	    wp->w_redr_status = TRUE;
-	    if (must_redraw < VALID)
-		must_redraw = VALID;
+	    if (must_redraw < UPD_VALID)
+		must_redraw = UPD_VALID;
 	}
 }
 
@@ -1149,7 +1149,7 @@
 # endif
 			)
 		    {
-			redraw_later(CLEAR);
+			redraw_later(UPD_CLEAR);
 			update_screen(0);
 			redrawcmd();
 		    }