PCI: Fix unaligned access in AF transaction pending test

pci_wait_for_pending() uses word access, so we shouldn't be passing
an offset that is only byte aligned.  Use the control register offset
instead, shifting the mask to match.

Fixes: d0b4cc4e3270 ("PCI: Wrong register used to check pending traffic")
Fixes: 157e876ffe0b ("PCI: Add pci_wait_for_pending() (refactor pci_wait_for_pending_transaction())
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
CC: stable@vger.kernel.org	# v3.14+
MAINTAINERS: Update mx6 PCI driver maintainer's email

Use Shawn's email address from Freescale.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Merge tag 'pci-v3.16-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fixes from Bjorn Helgaas:
 "Just a fix for the device reset path and an email address update.

  Virtualization
    - Fix "wait for pending transactions" for PCI AF reset (Alex
      Williamson)

  Miscellaneous
    - Update mx6 PCI driver maintainer email (Fabio Estevam)"

* tag 'pci-v3.16-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  MAINTAINERS: Update mx6 PCI driver maintainer's email
  PCI: Fix unaligned access in AF transaction pending test