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/if_py_both.h b/src/if_py_both.h
index 240cc96..b7276c5 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -697,7 +697,7 @@
 
     VimTryStart();
     do_cmdline_cmd(cmd);
-    update_screen(VALID);
+    update_screen(UPD_VALID);
 
     Python_Release_Vim();
     Py_END_ALLOW_THREADS
@@ -4067,7 +4067,7 @@
 	// When column is out of range silently correct it.
 	check_cursor_col_win(self->win);
 
-	update_screen(VALID);
+	update_screen(UPD_VALID);
 	return 0;
     }
     else if (strcmp(name, "height") == 0)
@@ -4745,7 +4745,7 @@
 
 	vim_free(str);
 	restore_win_for_buf(&switchwin, &save_curbuf);
-	update_screen(VALID);
+	update_screen(UPD_VALID);
 
 	if (VimTryEnd())
 	    return FAIL;
@@ -4816,7 +4816,7 @@
 	PyMem_Free(array);
 	restore_win_for_buf(&switchwin, &save_curbuf);
 
-	update_screen(VALID);
+	update_screen(UPD_VALID);
 
 	if (VimTryEnd())
 	    return FAIL;
@@ -5825,7 +5825,7 @@
     if (status)
 	return;
     check_cursor();
-    update_curbuf(NOT_VALID);
+    update_curbuf(UPD_NOT_VALID);
 }
 
     static void