git-remote documentation: fix synopsis to match description
git-remote documentation: fix synopsis to match description

In the text, the argument of -m is <master> which should be used in the
command synopsis, too.

Signed-off-by: Jörg Sommer <f49f2a5e660787beb1d0033eaaa9f0d533955c60@alea.gnuu.de>
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