minor clean up

Author: slandelle

src/main/java/com/ning/http/client/oauth/OAuthSignatureCalculator.java

@@ -239,8 +239,7 @@ public OAuthParameterSet(int size) {
         }
 
         public OAuthParameterSet add(String key, String value) {
-            Parameter p = new Parameter(key, value);
-            allParameters.add(p);
+            allParameters.add(new Parameter(key, value));
             return this;
         }