camerad: fix memory leak in create_thumbnail (#2743)

* fix memory leak in create_thumbnail

* free memory returned from jpeg_mem_dest

* OMG

selfdrive/camerad/cameras/camera_common.cc

@@ -296,8 +296,9 @@ void create_thumbnail(MultiCameraState *s, CameraState *c, uint8_t *bgr_ptr) {
     row_pointer[0] = row;
     jpeg_write_scanlines(&cinfo, row_pointer, 1);
   }
-  free(row);
   jpeg_finish_compress(&cinfo);
+  jpeg_destroy_compress(&cinfo);
+  free(row);
 
   MessageBuilder msg;
   auto thumbnaild = msg.initEvent().initThumbnail();
@@ -308,6 +309,7 @@ void create_thumbnail(MultiCameraState *s, CameraState *c, uint8_t *bgr_ptr) {
   if (s->pm != NULL) {
     s->pm->send("thumbnail", msg);
   }
+  free(thumbnail_buffer);
 }
 
 void set_exposure_target(CameraState *c, const uint8_t *pix_ptr, int x_start, int x_end, int x_skip, int y_start, int y_end, int y_skip) {