fixed run sample issue

Author: mahendya1002

samples/xml/src/main/java/com/cybersource/sample/RunSample.java

@@ -90,7 +90,7 @@ public static void main(String[] args) {
 
 		case 4:
 			authReply = runAuth(props, "auth");
-				if(authReply=null)
+				if(authReply==null)
 				break;
 			requestID = getRequestID(authReply);
 			decision = getDecisonCode(authReply);