Code cleanup

Author: smarek

library/src/com/loopj/android/http/AsyncHttpClient.java

@@ -921,7 +921,7 @@ private HttpEntity paramsToEntity(RequestParams params, AsyncHttpResponseHandler
             }
         } catch (Throwable t) {
             if (responseHandler != null)
-                responseHandler.sendFailureMessage(0, null, (byte[]) null, t);
+                responseHandler.sendFailureMessage(0, null, null, t);
             else
                 t.printStackTrace();
         }

library/src/com/loopj/android/http/AsyncHttpResponseHandler.java

@@ -225,7 +225,7 @@ public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
             onSuccess(statusCode, headers, response);
         } catch (UnsupportedEncodingException e) {
             Log.e(LOG_TAG, e.toString());
-            onFailure(statusCode, headers, e, (String) null);
+            onFailure(statusCode, headers, e, null);
         }
     }
 
@@ -290,7 +290,7 @@ public void onFailure(int statusCode, Header[] headers, Throwable error, String
      * @param error        the underlying cause of the failure
      */
     public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
-        String response = null;
+        String response;
         try {
             response = new String(responseBody, getCharset());
             onFailure(statusCode, headers, error, response);