firewire: mark some structs const

Instances of struct file_operations and struct fw_card_driver can be
qualified as "const".  Ditto with struct fw_descriptor.data, struct
fw_device_id, and predefined instances of struct fw_address_region,
at least in the current implementation.

Data qualified as const is placed into the .rodata section which won't
be mixed with dirty data.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-device-cdev.c b/drivers/firewire/fw-device-cdev.c
index c10e332..117bc6d 100644
--- a/drivers/firewire/fw-device-cdev.c
+++ b/drivers/firewire/fw-device-cdev.c
@@ -602,7 +602,7 @@
 		return 0;
 }
 
-struct file_operations fw_device_ops = {
+const struct file_operations fw_device_ops = {
 	.owner		= THIS_MODULE,
 	.open		= fw_device_op_open,
 	.read		= fw_device_op_read,