README simple doc fix

[gogolok]

--- a/README.markdown
+++ b/README.markdown
@@ -124,7 +124,7 @@ Here is a code sample:

        NSDictionary *dictionary = [NSDictionary dictionaryWithObject:@"b" forKey:@"a"];
        NSError *error = NULL;
-       NSData *jsonData = [[CJSONSerializer serializer] serializeObject:dictionary error&error];
+       NSData *jsonData = [[CJSONSerializer serializer] serializeObject:dictionary error:&error];

 ## Invalid JSON