fix some non-debug compile warnings

git-svn-id: svn://localhost/ardour2/branches/3.0@7293 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/ardour/ardour/source.h

@@ -106,8 +106,12 @@ class Source : public SessionObject
 
         void inc_use_count () { g_atomic_int_inc (&_use_count); }
         void dec_use_count () { 
+#ifndef NDEBUG
                 gint oldval = g_atomic_int_exchange_and_add (&_use_count, -1);
                 assert (oldval > 0);
+#else 
+                g_atomic_int_exchange_and_add (&_use_count, -1);
+#endif
         }
 
         int  use_count() const { return g_atomic_int_get (&_use_count); }

libs/ardour/audio_playlist.cc

@@ -41,8 +41,10 @@ using namespace PBD;
 AudioPlaylist::AudioPlaylist (Session& session, const XMLNode& node, bool hidden)
 	: Playlist (session, node, DataType::AUDIO, hidden)
 {
+#ifndef NDEBUG
 	const XMLProperty* prop = node.property("type");
 	assert(!prop || DataType(prop->value()) == DataType::AUDIO);
+#endif
 
 	in_set_state++;
 	set_state (node, Stateful::loading_state_version);