am, rebase: fix arghelp syntax of --empty

Use parentheses and pipes to present alternatives in the argument help
for the --empty options of git am and git rebase, like in the rest of
the documentation.

While at it remove a stray use of the enum empty_action value
STOP_ON_EMPTY_COMMIT to indicate that no short option is present.
While it has a value of 0 and thus there is no user-visible change,
that enum is not meant to hold short option characters.  Hard-code 0,
like we do for other options without a short option.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions