Small bugfix to logging.h from Scott Ettinger.
Small bugfix to logging.h from Scott Ettinger.

Change-Id: Ie6d51e7883adf36c6fc7a78ff95afab6a78e488b

ysonggit/ceres-solver,whuaegeanse/ceres-solver,ysonggit/ceres-solver,DougFirErickson/ceres-solver,kartikkumar/ceres-solver,timfel/ceres-bin,kartikkumar/ceres-solver,entylop/ceres-solver,stonier/ceres_solver,whuaegeanse/ceres-solver,entylop/ceres-solver,ysonggit/ceres-solver,DougFirErickson/ceres-solver,entylop/ceres-solver,ysonggit/ceres-solver,entylop/ceres-solver,kartikkumar/ceres-solver,ikoruk/ceres-solver,ikoruk/ceres-solver,stonier/ceres_solver,stonier/ceres_solver,kartikkumar/ceres-solver,DougFirErickson/ceres-solver,stonier/ceres_solver,ikoruk/ceres-solver,whuaegeanse/ceres-solver,ikoruk/ceres-solver,ikoruk/ceres-solver,timfel/ceres-bin,whuaegeanse/ceres-solver,timfel/ceres-bin,DougFirErickson/ceres-solver,timfel/ceres-bin