Call explicitly cancel.

backend/escl/escl.c

@@ -843,6 +843,7 @@ sane_start(SANE_Handle h)
     DBG(10, "2-Size Image [%dx%d|%dx%d]\n", 0, 0, w, he);
     if (handler->scanner->source > 0)
       escl_scanner(handler->name, handler->result);
+
     if (status != SANE_STATUS_GOOD)
         return (status);
     handler->ps.depth = 8;