MSI: Use correct data offset for 32-bit MSI in read_msi_msg()

patch cbf5d9e6 in mainline.

While reading the MSI code trying to find a reason why MSI wouldn't
work for devices that have a 32-bit MSI address capability, I noticed
that read_msi_msg() seems to read the message data from the wrong
offset in this case.
Signed-off-by: Roland Dreier <roland@digitalvampire.org>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/msi.c

@@ -132,7 +132,7 @@ void read_msi_msg(unsigned int irq, struct msi_msg *msg)
 			pci_read_config_word(dev, msi_data_reg(pos, 1), &data);
 		} else {
 			msg->address_hi = 0;
-			pci_read_config_word(dev, msi_data_reg(pos, 1), &data);
+			pci_read_config_word(dev, msi_data_reg(pos, 0), &data);
 		}
 		msg->data = data;
 		break;