git-p4: Fix checkout bug when using --import-local.
git-p4: Fix checkout bug when using --import-local.

When this option is passed to git p4 clone, the checkout at the end would
previously fail. This patch fixes it by optionally creating the master branch
from refs/heads/p4/master, which is the correct one for this option.

Signed-off-by: Tor Arvid Lund <10881b5c954573e37687444135aa1ca5b764260c@gmail.com>
Acked-By: Simon Hausmann <088e16a1019277b15d58faf0541e11910eb756f6@lst.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