lvgldemo: should use nuttx_deinit to free all resources

Memory leak can be detected when simply change the while(1) loop to exit. The lv_nuttx_deinit will free resources including display, input etc.

Signed-off-by: Neo Xu <neo.xu1990@gmail.com>

Author: XuNeo

examples/lvgldemo/lvgldemo.c

@@ -162,7 +162,7 @@ int main(int argc, FAR char *argv[])
 #endif
 
 demo_end:
-  lv_disp_remove(result.disp);
+  lv_nuttx_deinit(&result);
   lv_deinit();
 
   return 0;