Merge tag 'stable/for-linus-3.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fixes from David Vrabel:
 "Xen regression and bug fixes for 3.15-rc1:

   - fix completely broken 32-bit PV guests caused by x86 refactoring
     32-bit thread_info.
   - only enable ticketlock slow path on Xen (not bare metal)
   - fix two bugs with PV guests not shutting down when requested
   - fix a minor memory leak in xen-pciback error path"

* tag 'stable/for-linus-3.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/manage: Poweroff forcefully if user-space is not yet up.
  xen/xenbus: Avoid synchronous wait on XenBus stalling shutdown/restart.
  xen/spinlock: Don't enable them unconditionally.
  xen-pciback: silence an unwanted debug printk
  xen: fix memory leak in __xen_pcibk_add_pci_dev()
  x86/xen: Fix 32-bit PV guests's usage of kernel_stack