T62446: Mouse cursor disappears on Grease Pencil stroke

Before the cursor was only visible after the cursor moves over side areas, but not in viewport area.

Now, as soon the drawing is completed, the cursor is reset in order to get again the icon in the viewport.

source/blender/editors/gpencil/gpencil_paint.c

@@ -2392,6 +2392,8 @@ static void gpencil_draw_exit(bContext *C, wmOperator *op)
 		gpencil_undo_finish();
 
 		/* cleanup */
+		WM_cursor_modal_set(p->win, CURSOR_STD);
+
 		gp_paint_cleanup(p);
 		gp_session_cleanup(p);
 		ED_gpencil_toggle_brush_cursor(C, true, NULL);