Add debug messages to process.c

src/core/process.c

  * @v process		Process
  */
 void process_add ( struct process *process ) {
+	DBGC ( process, "PROCESS %p starting\n", process );
 	ref_get ( process->refcnt );
 	list_add_tail ( &process->list, &run_queue );
 }
  */
 void process_del ( struct process *process ) {
 	if ( ! list_empty ( &process->list ) ) {
+		DBGC ( process, "PROCESS %p stopping\n", process );
 		list_del ( &process->list );
 		INIT_LIST_HEAD ( &process->list );
 		ref_put ( process->refcnt );
+	} else {
+		DBGC ( process, "PROCESS %p already stopped\n", process );
 	}
 }