chan_sip.c: Simplify sip_pvt destructor call levels.

Remove destructor calling destroy_it calling really_destroy_it
for no benefit.  Just make the destructor the really_destroy_it
function.

Change-Id: Idea0d47b27dd74f2488db75bcc7f353d8fdc614a

channels/chan_sip.c

@@ -6381,11 +6381,14 @@ static void offered_media_list_destroy(struct sip_pvt *p)
 	}
 }
-/*! \brief Execute destruction of SIP dialog structure, release memory */
-void __sip_destroy(struct sip_pvt *p, int lockowner, int lockdialoglist)
+/*! \brief ao2 destructor for SIP dialog structure */
+static void sip_pvt_dtor(void *vdoomed)
 {
+	struct sip_pvt *p = vdoomed;
 	struct sip_request *req;
+	ast_debug(3, "Destroying SIP dialog %s\n", p->callid);
+
 	/* Destroy Session-Timers if allocated */
  	if (p->stimer) {
 		p->stimer->quit_flag = 1;
@@ -6404,14 +6407,12 @@ void __sip_destroy(struct sip_pvt *p, int lockowner, int lockdialoglist)
 	/* Unlink us from the owner if we have one */
 	if (p->owner) {
-		if (lockowner)
-			ast_channel_lock(p->owner);
+		ast_channel_lock(p->owner);
 		ast_debug(1, "Detaching from %s\n", ast_channel_name(p->owner));
 		ast_channel_tech_pvt_set(p->owner, NULL);
 		/* Make sure that the channel knows its backend is going away */
 		ast_channel_softhangup_internal_flag_add(p->owner, AST_SOFTHANGUP_DEV);
-		if (lockowner)
-			ast_channel_unlock(p->owner);
+		ast_channel_unlock(p->owner);
 		/* Give the channel a chance to react before deallocation */
 		usleep(1);
 	}
@@ -6716,24 +6717,6 @@ static int update_call_counter(struct sip_pvt *fup, int event)
 	return 0;
 }
-
-static void sip_destroy_fn(void *p)
-{
-	sip_destroy(p);
-}
-
-/*! \brief Destroy SIP call structure.
- * Make it return NULL so the caller can do things like
- *	foo = sip_destroy(foo);
- * and reduce the chance of bugs due to dangling pointers.
- */
-struct sip_pvt *sip_destroy(struct sip_pvt *p)
-{
-	ast_debug(3, "Destroying SIP dialog %s\n", p->callid);
-	__sip_destroy(p, TRUE, TRUE);
-	return NULL;
-}
-
 /*! \brief Convert SIP hangup causes to Asterisk hangup causes */
 int hangup_sip2cause(int cause)
 {
@@ -8635,7 +8618,7 @@ struct sip_pvt *__sip_alloc(ast_string_field callid, struct ast_sockaddr *addr,
 {
 	struct sip_pvt *p;
-	p = __ao2_alloc(sizeof(*p), sip_destroy_fn,
+	p = __ao2_alloc(sizeof(*p), sip_pvt_dtor,
 		AO2_ALLOC_OPT_LOCK_MUTEX, "allocate a dialog(pvt) struct",
 		file, line, func);
 	if (!p) {

channels/sip/include/dialog.h

@@ -43,19 +43,6 @@ void sip_scheddestroy_final(struct sip_pvt *p, int ms);
 void sip_scheddestroy(struct sip_pvt *p, int ms);
 int sip_cancel_destroy(struct sip_pvt *p);
 
-/*! \brief Destroy SIP call structure.
- * Make it return NULL so the caller can do things like
- *	foo = sip_destroy(foo);
- * and reduce the chance of bugs due to dangling pointers.
- */
-struct sip_pvt *sip_destroy(struct sip_pvt *p);
-
-/*! \brief Destroy SIP call structure.
- * Make it return NULL so the caller can do things like
- *	foo = sip_destroy(foo);
- * and reduce the chance of bugs due to dangling pointers.
- */
-void __sip_destroy(struct sip_pvt *p, int lockowner, int lockdialoglist);
 /*!
  * \brief Unlink a dialog from the dialogs container, as well as any other places
  * that it may be currently stored.