xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK

PCI_MSIX_FLAGS_BIRMASK is mis-named because the BIR mask is in the
Table Offset register, not the flags ("Message Control" per spec)
register.

Acked-by: Jan Beulich <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
CC: Konrad Rzeszutek Wilk <[e-mail]>
Signed-off-by: Konrad Rzeszutek Wilk <[e-mail]>

arch/x86/pci/xen.c

···
 
 			pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
 					      &table_offset);
-			bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
+			bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
 
 			map_irq.table_base = pci_resource_start(dev, bir);
 			map_irq.entry_nr = msidesc->msi_attrib.entry_nr;