Fix use-after-move in //device/fido/fido_device_authenticator.cc

Fix use-after-move (potential) bugs found by the
"bugprone-use-after-move" clang-tidy check.

Bug: 1122844
Change-Id: Iad9f9a167eda67d20d9e99861804a1f2183fe3fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2385455Reviewed-by: Adam Langley <agl@chromium.org>
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803212}

device/fido/fido_device_authenticator.cc

@@ -230,6 +230,7 @@ void FidoDeviceAuthenticator::OnHaveEphemeralKey(
     base::Optional<pin::KeyAgreementResponse> key) {
   if (status != CtapDeviceResponseCode::kSuccess) {
     std::move(callback).Run(status, base::nullopt);
+    return;
   }
   DCHECK(key.has_value());