DM RAID: Fix comparison of index and quantity for "rebuild" parameter

DM RAID: Fix comparison of index and quantity for "rebuild" parameter

The "rebuild" parameter takes an index argument that starts counting from
zero.  The conditional used to validate the index was using '>' rather than
'>=', leaving the door open for an index value that would be 1 too large.
Reported-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

drivers/md/dm-raid.c

@@ -539,7 +539,7 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
 
 		/* Parameters that take a numeric value are checked here */
 		if (!strcasecmp(key, "rebuild")) {
-			if (value > rs->md.raid_disks) {
+			if (value >= rs->md.raid_disks) {
 				rs->ti->error = "Invalid rebuild index given";
 				return -EINVAL;
 			}