Fix error_processor_test.dart's use of USE_OF_VOID_RESULT.
Fix error_processor_test.dart's use of USE_OF_VOID_RESULT.

The message for this error code doesn't accept any arguments, so
there's no reason for the test to provide any.

Change-Id: I6306cead7865704c9074dd0dc2a1bc1aacaeda16
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/213724
Reviewed-by: Konstantin Shcheglov <09e4d7516628963212bf4aace2f97603d2b706e4@google.com>
Commit-Queue: Paul Berry <72d414e3a99fb120308437779d51667bcc0984eb@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk