RFR: 8166781: fix wrong comment in ReceiverTypeData

[Roland Schatz]

Hi,

Please review this comment fix:

webrev: http://cr.openjdk.java.net/~rschatz/JDK-8166781/webrev.00/
issue: https://bugs.openjdk.java.net/browse/JDK-8166781

According to my reading of the code, the comment should now agree with 
the code.
But I don't pretend to really understand that code. It would be nice if 
someone who knows about the profiling code could confirm that's actually 
true ;)

See also previous thread about that issue:
http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2016-August/024105.html

Thanks,
Roland