The sequencer already knew how to fast-forward instead of
cherry-picking, if possible.
We want to continue to do this, of course, but in case of the 'reword'
command, we will need to call `git commit` after fast-forwarding.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>