Fix test of incorrect SDK path.

pkg/analyzer/lib/src/dart/sdk/sdk.dart

Index: pkg/analyzer/lib/src/dart/sdk/sdk.dart
diff --git a/pkg/analyzer/lib/src/dart/sdk/sdk.dart b/pkg/analyzer/lib/src/dart/sdk/sdk.dart
index fc1a2d3c7493611163430792533bcf21a3701515..1163413d4d13f662ea9dff7cb9d317693b480b01 100644
--- a/pkg/analyzer/lib/src/dart/sdk/sdk.dart
+++ b/pkg/analyzer/lib/src/dart/sdk/sdk.dart
@@ -703,7 +703,7 @@ class FolderBasedDartSdk extends AbstractDartSdk {
       // *built* SDK if possible.
       String builtSdkPath =
           pathContext.join(pathContext.dirname(exec), 'dart-sdk');
-      if (resourceProvider.getFolder(sdkPath).exists) {
+      if (resourceProvider.getFolder(builtSdkPath).exists) {
         return builtSdkPath;
       } else {
         return sdkPath;