linear: correct disk numbering error check

From: "Nikanth Karthikesan" <knikanth@novell.com>

Correct disk numbering problem check.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Neil Brown <neilb@suse.de>

drivers/md/linear.c

@@ -126,7 +126,7 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
 		int j = rdev->raid_disk;
 		dev_info_t *disk = conf->disks + j;
 
-		if (j < 0 || j > raid_disks || disk->rdev) {
+		if (j < 0 || j >= raid_disks || disk->rdev) {
 			printk("linear: disk numbering problem. Aborting!\n");
 			goto out;
 		}