uevent: Fix clippy issue in test code

Remove a bare `return` from a test function. This looks wrong but isn't
because the callers are all tests that just wait for a state change
caused by this test function.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

src/agent/src/uevent.rs

@@ -240,7 +240,6 @@ pub(crate) fn spawn_test_watcher(sandbox: Arc<Mutex<Sandbox>>, uev: Uevent) {
                     if matcher.is_match(&uev) {
                         let (_, sender) = watch.take().unwrap();
                         let _ = sender.send(uev.clone());
-                        return;
                     }
                 }
             });