Reduce dynamic allocation from 3 to 1 per log message

This patch was contributed in

https://code.google.com/p/google-glog/issues/detail?id=131

by engel. Thanks!


git-svn-id: http://google-glog.googlecode.com/svn/trunk@136 eb4d4688-79bd-11dd-afb4-1d65580434c0