RFR(XS): 8159917: Added missing space to class+loader+data logging

[Max Ockner]

Hello,
Please review this small correction to class+loader+data logging.

bug: https://bugs.openjdk.java.net/browse/JDK-8159917
webrev:  http://cr.openjdk.java.net/~mockner/8159917/

Previously in ClassLoaderData::print_value_on(), there was a space 
missing between the hex address and the letter 'a' as part of a separate 
field in the logging info. This space has been removed.

Thanks,
Max