Fixes default logs location for STC.

Change-Id: If3f41f6df527d57d13bb75f91ce508f3cef7e73b
diff --git a/utils/stc/src/main/java/org/onlab/stc/Compiler.java b/utils/stc/src/main/java/org/onlab/stc/Compiler.java
index c2a0c81..add71eb 100644
--- a/utils/stc/src/main/java/org/onlab/stc/Compiler.java
+++ b/utils/stc/src/main/java/org/onlab/stc/Compiler.java
@@ -42,7 +42,7 @@
  */
 public class Compiler {
 
-    private static final String DEFAULT_LOG_DIR = "${env.WORKSPACE}/tmp/stc/";
+    private static final String DEFAULT_LOG_DIR = "${WORKSPACE}/tmp/stc/";
 
     private static final String IMPORT = "import";
     private static final String GROUP = "group";