IPMI: make ipmi_poweroff_handler const

Make this const as it is only passed to a const argument of the function
ipmi_create_user.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

drivers/char/ipmi/ipmi_poweroff.c

@@ -133,7 +133,7 @@ static void receive_handler(struct ipmi_recv_msg *recv_msg, void *handler_data)
 		complete(comp);
 }
 
-static struct ipmi_user_hndl ipmi_poweroff_handler = {
+static const struct ipmi_user_hndl ipmi_poweroff_handler = {
 	.ipmi_recv_hndl = receive_handler
 };