aacraid: IOCTL pass-through command fix

The Linux aacriad driver fails to detect the case of SG list count=0 on IOCTL
pass-through command and cause intermittent fault.  The result is the Linux
aacriad driver send down IOCTL pass-through command with one not initialized
SG list to firmware when receiving SG list count =0 on pass-through command.
Signed-off-by: Mahesh Rajashekhara <Mahesh.Rajashekhara@pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Murthy Bhat <Murthy.Bhat@pmcs.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

drivers/scsi/aacraid/commctrl.c

@@ -689,7 +689,10 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 			kfree (usg);
 		}
 		srbcmd->count = cpu_to_le32(byte_count);
+		if (user_srbcmd->sg.count)
 			psg->count = cpu_to_le32(sg_indx+1);
+		else
+			psg->count = 0;
 		status = aac_fib_send(ScsiPortCommand64, srbfib, actual_fibsize, FsaNormal, 1, 1,NULL,NULL);
 	} else {
 		struct user_sgmap* upsg = &user_srbcmd->sg;
@@ -775,7 +778,10 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 			}
 		}
 		srbcmd->count = cpu_to_le32(byte_count);
+		if (user_srbcmd->sg.count)
 			psg->count = cpu_to_le32(sg_indx+1);
+		else
+			psg->count = 0;
 		status = aac_fib_send(ScsiPortCommand, srbfib, actual_fibsize, FsaNormal, 1, 1, NULL, NULL);
 	}
 	if (status == -ERESTARTSYS) {