double gradOutput alloc in max-pool fix
double gradOutput alloc in max-pool fix

lukasc-ch/cunn,andreaskoepf/cunn,clementfarabet/cunn,szagoruyko/cunn,rotmanmi/cunn,apaszke/cunn,lukasc-ch/cunn,jhjin/cunn,clementfarabet/cunn,jonathantompson/cunn,danielsig727/cunn,apaszke/cunn,jhjin/cunn,rotmanmi/cunn,andreaskoepf/cunn,szagoruyko/cunn,colesbury/cunn,colesbury/cunn,jonathantompson/cunn,colesbury/cunn,apaszke/cunn