audio/avrcp: Fix not setting player id

The id shall be initialized properly otherwise it maybe reused by
another player since its id will be 0 which is reserved as placeholder
when discovering the player list.
diff --git a/profiles/audio/avrcp.c b/profiles/audio/avrcp.c
index c100149..90faa1d 100644
--- a/profiles/audio/avrcp.c
+++ b/profiles/audio/avrcp.c
@@ -3212,6 +3212,7 @@
 	const char *path;
 
 	player = g_new0(struct avrcp_player, 1);
+	player->id = id;
 	player->sessions = g_slist_prepend(player->sessions, session);
 
 	path = device_get_path(session->dev);