Fix LoginAuthUserView unneeded RepeatingCallback

This is a tiny cleanup that replaces a RepeatingCallback with a
OnceCallback in the place where it wasn't needed (OneShotTimer in
ash::LoginAuthUserView::ChallengeResponseView).

Bug: 983103
Change-Id: Iad4c5a8755e1a8f6fb087bae54af93122fde58e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2020933Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735912}

ash/login/ui/login_auth_user_view.cc

@@ -604,8 +604,8 @@ class LoginAuthUserView::ChallengeResponseView : public views::View,
     if (state == State::kFailure) {
       reset_state_timer_.Start(
           FROM_HERE, kChallengeResponseResetAfterFailureDelay,
-          base::BindRepeating(&ChallengeResponseView::SetState,
-                              base::Unretained(this), State::kInitial));
+          base::BindOnce(&ChallengeResponseView::SetState,
+                         base::Unretained(this), State::kInitial));
     }
 
     arrow_button_->EnableLoadingAnimation(state == State::kAuthenticating);