Cleanup lingering mention of GMB

[Claes Redestad]

Hi,

I spotted some remnants of the @GenerateMicroBenchmark/@GMB annotation 
in one
of the JMH samples, which might be confusing. I took a stab at cleaning 
this
up and remove all mention of @GMB/gmb from the sources while I was at it:

http://cr.openjdk.java.net/~redestad/jmh/gmb.webrev

Feel free to take this patch into consideration.

Thanks!

/Claes