Remove some unused variables and properties

Author: tgalopin

Encoder/JsonDecode.php

@@ -24,7 +24,6 @@ class JsonDecode implements DecoderInterface
 
     private $associative;
     private $recursionDepth;
-    private $lastError = JSON_ERROR_NONE;
 
     /**
      * Constructs a new JsonDecode instance.
@@ -75,7 +74,7 @@ public function decode($data, $format, array $context = array())
 
         $decodedData = json_decode($data, $associative, $recursionDepth, $options);
 
-        if (JSON_ERROR_NONE !== $this->lastError = json_last_error()) {
+        if (JSON_ERROR_NONE !== json_last_error()) {
             throw new UnexpectedValueException(json_last_error_msg());
         }
 

Encoder/JsonEncode.php

@@ -21,7 +21,6 @@
 class JsonEncode implements EncoderInterface
 {
     private $options;
-    private $lastError = JSON_ERROR_NONE;
 
     public function __construct($bitmask = 0)
     {
@@ -39,7 +38,7 @@ public function encode($data, $format, array $context = array())
 
         $encodedJson = json_encode($data, $context['json_encode_options']);
 
-        if (JSON_ERROR_NONE !== $this->lastError = json_last_error()) {
+        if (JSON_ERROR_NONE !== json_last_error()) {
             throw new UnexpectedValueException(json_last_error_msg());
         }