analyzer_cli: Remove unnecessary imports

Bug: #44569
Change-Id: I621f187a7ec654235b21a77f28258bba7ef8c179
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/177300
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Samuel Rawlins <[email protected]>

Author: srawlins

pkg/analyzer_cli/lib/src/driver.dart

@@ -22,7 +22,6 @@ import 'package:analyzer/src/dart/analysis/file_state.dart';
 import 'package:analyzer/src/dart/analysis/performance_logger.dart';
 import 'package:analyzer/src/dart/analysis/results.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart';
-import 'package:analyzer/src/file_system/file_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/interner.dart';
 import 'package:analyzer/src/generated/java_engine.dart';

pkg/analyzer_cli/tool/perf.dart

@@ -17,7 +17,6 @@ import 'package:analyzer/src/context/packages.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart' show FolderBasedDartSdk;
-import 'package:analyzer/src/file_system/file_system.dart';
 import 'package:analyzer/src/generated/parser.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';