Revert "boilerplate/setup: introduce destructors for __setup_call"

In fact we would need real destructors for all setup_descriptor s. Stop
pretending that we know how to dlclose or destruct.

This reverts commit 5511e760.

include/boilerplate/setup.h

@@ -78,16 +78,10 @@ struct setup_descriptor {
 #define __early_ctor		__attribute__ ((constructor(210)))
 #define __bootstrap_ctor	__attribute__ ((constructor(220)))
 
-#define __setup_dtor		__attribute__ ((destructor(200)))
-
 #define __setup_call(__name, __id)			\
 static __setup_ctor void __declare_ ## __name(void)	\
 {							\
 	__register_setup_call(&(__name), __id);		\
-}							\
-static __setup_dtor void __undeclare_ ## __name(void)	\
-{							\
-	__unregister_setup_call(&(__name), __id);	\
 }
 
 #define core_setup_call(__name)		__setup_call(__name, 0)
@@ -102,7 +96,6 @@ extern "C" {
 #endif
 
 void __register_setup_call(struct setup_descriptor *p, int id);
-void __unregister_setup_call(struct setup_descriptor *p, int id);
 
 extern pid_t __node_id;
 

lib/boilerplate/setup.c

@@ -701,12 +701,6 @@ void __register_setup_call(struct setup_descriptor *p, int id)
 	pvlist_prepend(&p->__reserved.next, &setup_list);
 }
 
-void __unregister_setup_call(struct setup_descriptor *p, int id)
-{
-	pvlist_remove(&p->__reserved.next);
-}
-
-
 const char *get_program_name(void)
 {
 	return basename(__base_setup_data.arg0 ?: "program");