PCI/DPC: Push dpc->rp_pio_status assignment into dpc_rp_pio_get_info()

Move the dpc->rp_pio_status assignment into dpc_rp_pio_get_info() since
that's where we read rp_pio->status anway.  No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sinan Kaya <okaya@codeaurora.org>