D7641: rebase: use cmdutil.check_at_most_one_arg() for --confirm/--dry-run

[pulkit (Pulkit Goyal)]

pulkit added inline comments.

INLINE COMMENTS

> cmdutil.py:272
>              if previous:
>                  raise error.Abort(
>                      _(b'cannot specify both --%s and --%s') % (previous, x)

Spotted in a later patch, need to replace `_` back to `-` before printing output.

REPOSITORY
  rHG Mercurial

BRANCH
  default

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7641/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7641

To: martinvonz, #hg-reviewers, pulkit
Cc: mercurial-devel