Correctly use sdk passed on command-line

pkg/analysis_server/lib/src/server/driver.dart

Index: pkg/analysis_server/lib/src/server/driver.dart
diff --git a/pkg/analysis_server/lib/src/server/driver.dart b/pkg/analysis_server/lib/src/server/driver.dart
index dc2ac7f9b7375675486330528c907a81d44ec7f1..dc971b89deb62a27a66d5acc4f124eca28335cdd 100644
--- a/pkg/analysis_server/lib/src/server/driver.dart
+++ b/pkg/analysis_server/lib/src/server/driver.dart
@@ -425,8 +425,8 @@ class Driver implements ServerStarter {
     SdkCreator defaultSdkCreator = (AnalysisOptions options) {
       PhysicalResourceProvider resourceProvider =
           PhysicalResourceProvider.INSTANCE;
-      FolderBasedDartSdk sdk = new FolderBasedDartSdk(resourceProvider,
-          FolderBasedDartSdk.defaultSdkDirectory(resourceProvider));
+      FolderBasedDartSdk sdk = new FolderBasedDartSdk(
+          resourceProvider, resourceProvider.getFolder(defaultSdkPath));
       sdk.analysisOptions = options;
       sdk.useSummary = useSummaries;
       return sdk;