regression: request-pull with signed tag lacks tags/ in master

["Michael S. Tsirkin" <mst@redhat.com>]

looks like pull requests with signed git got broken in git master:

[mst@robin qemu]$ /usr/bin/git --version
git version 1.8.3.1
[mst@robin qemu]$ git --version
git version 2.0.0.rc1.18.gac53fc6.dirty
[mst@robin qemu]$ 
[mst@robin qemu]$ /usr/bin/git request-pull origin/master git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git for_upstream |grep git.kernel.org
  git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream


[mst@robin qemu]$ git request-pull origin/master git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git for_upstream |grep git.kernel.org
  git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git for_upstream

this for_upstream syntax is a problem because it does not work
for older git clients who might get this request.

Didn't bisect yet - anyone knows what broke this?

-- 
MST