[SCSI] aacraid: add optional MSI support

Added support for MSI utilizing the aacraid.msi=1 parameter. This
patch adds some localized or like-minded janitor fixes. Since the
default is disabled, there is no impact on the code paths unless the
customer wishes to experiment with the MSI performance.

Signed-off-by: Mark Salyzyn <aacraid@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
index 3195d29..ace0b75 100644
--- a/drivers/scsi/aacraid/aacraid.h
+++ b/drivers/scsi/aacraid/aacraid.h
@@ -1026,6 +1026,7 @@
 	u8			raw_io_64;
 	u8			printf_enabled;
 	u8			in_reset;
+	u8			msi;
 };
 
 #define aac_adapter_interrupt(dev) \
@@ -1881,6 +1882,7 @@
 extern int aif_timeout;
 extern int expose_physicals;
 extern int aac_reset_devices;
+extern int aac_msi;
 extern int aac_commit;
 extern int update_interval;
 extern int check_interval;