Fix bugs in extension treatment REST API

Change-Id: If47f5ffce634617200e765be72c7898d984b0786
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/InstructionCodec.java b/core/common/src/main/java/org/onosproject/codec/impl/InstructionCodec.java
index da41e25..9da240d 100644
--- a/core/common/src/main/java/org/onosproject/codec/impl/InstructionCodec.java
+++ b/core/common/src/main/java/org/onosproject/codec/impl/InstructionCodec.java
@@ -77,6 +77,6 @@
             return null;
         }
 
-        return new DecodeInstructionCodecHelper(json).decode();
+        return new DecodeInstructionCodecHelper(json, context).decode();
     }
 }