RFR (14) 8237370: Javadoc of memory access API still refers to old MemoryAddress::offset method

[Maurizio Cimadamore]

Small patch which fixes some @code snippets still showing 
MemoryAddress::offset(long) instead of MemoryAddress::addOffset(long)

Webrev:
http://cr.openjdk.java.net/~mcimadamore/8237370/

Cheers
Maurizio