firewire: Fix another typo from the bitfield conversion.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/fw-ohci.c

@@ -1352,7 +1352,7 @@ ohci_queue_iso(struct fw_iso_context *base,
 	else
 		irq = descriptor_no_irq;
 
-	last->control = cpu_to_le16(descriptor_output_last |
+	last->control |= cpu_to_le16(descriptor_output_last |
 				     descriptor_status |
 				     descriptor_branch_always |
 				     irq);