make extensions linkable (thanks mishehu)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@1537 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/include/switch_caller.h

@@ -112,6 +112,7 @@ struct switch_caller_extension {
 	switch_caller_application_t *last_application;
 	/*! Pointer to the entire stack of applications for this extension */
 	switch_caller_application_t *applications;
+	struct switch_caller_extension *next;
 };
 
 /*!

src/switch_channel.c

@@ -757,7 +757,11 @@ SWITCH_DECLARE(void) switch_channel_set_caller_extension(switch_channel_t *chann
 														 switch_caller_extension_t *caller_extension)
 {
 	assert(channel != NULL);
+
+	switch_mutex_lock(channel->profile_mutex);
+	caller_extension->next = channel->caller_extension;
 	channel->caller_extension = caller_extension;
+	switch_mutex_unlock(channel->profile_mutex);
 }