git-push.txt: document the behavior of --repo
git-push.txt: document the behavior of --repo

As per the code, the --repo <repo> option is equivalent to the
<repo> argument to 'git push', but somehow it was documented as
something that is more than that.  [It exists for historical
reasons, back from the time when options had to come before
arguments.]

Say so. [But not that.]

Signed-off-by: Michael J Gruber <46f1a0bd5592a2f9244ca321b129902a06b53e03@drmicha.warpmail.net>
Helped-by: Eric Sunshine <8d6e34f987851aa599257d3831a1af040886842f@sunshineco.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git