ipmi: Remove usecount function from interfaces

All the users are now gone.
Signed-off-by: Corey Minyard <cminyard@mvista.com>

include/linux/ipmi_smi.h

@@ -140,15 +140,6 @@ struct ipmi_smi_handlers {
 	 * block.
 	 */
 	void (*set_maintenance_mode)(void *send_info, bool enable);
-
-	/*
-	 * Tell the handler that we are using it/not using it.  The
-	 * message handler get the modules that this handler belongs
-	 * to; this function lets the SMI claim any modules that it
-	 * uses.  These may be NULL if this is not required.
-	 */
-	int (*inc_usecount)(void *send_info);
-	void (*dec_usecount)(void *send_info);
 };
 
 struct ipmi_device_id {