PCI/MSI: bugfix/utilize for msi_capability_init()

This patch fix a following bug and does a cleanup.

bug:
commit 5993760f7fc75b77e4701f1e56dc84c0d6cf18d5
had a wrong change (since is_64 is boolean[0|1]):

- pci_write_config_dword(dev,
- msi_mask_bits_reg(pos, is_64bit_address(control)),
- maskbits);
+ pci_write_config_dword(dev, entry->msi_attrib.is_64, maskbits);

utilize:
Unify separated if (entry->msi_attrib.maskbit) statements.

Signed-off-by: Hidetoshi Seto <[e-mail]>
Acked-by: "Jike Song" <[e-mail]>
Cc: [e-mail]
Signed-off-by: Jesse Barnes <[e-mail]>

drivers/pci/msi.c

···
 	entry->msi_attrib.masked = 1;
 	entry->msi_attrib.default_irq = dev->irq;	/* Save IOAPIC IRQ */
 	entry->msi_attrib.pos = pos;
-	if (entry->msi_attrib.maskbit) {
-		entry->mask_base = (void __iomem *)(long)msi_mask_bits_reg(pos,
-				entry->msi_attrib.is_64);
-	}
 	entry->dev = dev;
 	if (entry->msi_attrib.maskbit) {
-		unsigned int maskbits, temp;
+		unsigned int base, maskbits, temp;
+
+		base = msi_mask_bits_reg(pos, entry->msi_attrib.is_64);
+		entry->mask_base = (void __iomem *)(long)base;
+
 		/* All MSIs are unmasked by default, Mask them all */
-		pci_read_config_dword(dev,
-			msi_mask_bits_reg(pos, entry->msi_attrib.is_64),
-			&maskbits);
+		pci_read_config_dword(dev, base, &maskbits);
 		temp = (1 << multi_msi_capable(control));
 		temp = ((temp - 1) & ~temp);
 		maskbits |= temp;
-		pci_write_config_dword(dev, entry->msi_attrib.is_64, maskbits);
+		pci_write_config_dword(dev, base, maskbits);
 		entry->msi_attrib.maskbits_mask = temp;
 	}
 	list_add_tail(&entry->list, &dev->msi_list);