mailbox: ti-msgmgr: Off by one in ti_msgmgr_of_xlate()

The > comparison should be >= or we access one element beyond the end
of the array.

(The inst->qinsts[] array is allocated in the ti_msgmgr_probe() function
and it has ->num_valid_queues elements.)

Fixes: a2b79838 ("mailbox: ti-msgmgr: Add support for Secure Proxy")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/ti-msgmgr.c

@@ -547,7 +547,7 @@ static struct mbox_chan *ti_msgmgr_of_xlate(struct mbox_controller *mbox,
 	}
 
 	if (d->is_sproxy) {
-		if (req_pid > d->num_valid_queues)
+		if (req_pid >= d->num_valid_queues)
 			goto err;
 		qinst = &inst->qinsts[req_pid];
 		return qinst->chan;