Update cupy/_core/_routines_math.pyx
Update cupy/_core/_routines_math.pyx

Co-authored-by: Kenichi Maehashi <767adca4ce92993afe6a6ac3caaa939f55013b96@users.noreply.github.com>
cupy/cupy,cupy/cupy,cupy/cupy,cupy/cupy