Merge tag 'stable/for-linus-3.16-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fix from David Vrabel:
 "Fix BUG when trying to expand the grant table.  This seems to occur
  often during boot with Ubuntu 14.04 PV guests"

* tag 'stable/for-linus-3.16-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: safely map and unmap grant frames when in atomic context