Fixed Affine transform typedef.
Fixed Affine transform typedef.

mjbshaw/Eigen,madlib/eigen_backup,rotorliu/eigen,madlib/eigen_backup,mjbshaw/Eigen,mjbshaw/Eigen,rotorliu/eigen,madlib/eigen_backup,rotorliu/eigen,madlib/eigen_backup,rotorliu/eigen,mjbshaw/Eigen