drop get_net_downlink_format_cb

It seems to be a remnant from early openbsc_mgcp. There is only the
default implementation for this callback and it simply returns two
pointers. Simplify that.

Change-Id: I18dfd44c931540caf4ac360c08ed10e5f65b2165
diff --git a/include/osmocom/mgcp/mgcp.h b/include/osmocom/mgcp/mgcp.h
index 224d756..42d67cf 100644
--- a/include/osmocom/mgcp/mgcp.h
+++ b/include/osmocom/mgcp/mgcp.h
@@ -138,8 +138,6 @@
 	mgcp_processing rtp_processing_cb;
 	mgcp_processing_setup setup_rtp_processing_cb;
 
-	mgcp_get_format get_net_downlink_format_cb;
-
 	struct osmo_wqueue gw_fd;
 
 	struct mgcp_port_range net_ports;
diff --git a/src/libosmo-mgcp/mgcp_network.c b/src/libosmo-mgcp/mgcp_network.c
index e37437d..111c5cf 100644
--- a/src/libosmo-mgcp/mgcp_network.c
+++ b/src/libosmo-mgcp/mgcp_network.c
@@ -429,18 +429,6 @@
 	return 0;
 }
 
-void mgcp_get_net_downlink_format_default(struct mgcp_endpoint *endp,
-					  const struct mgcp_rtp_codec **codec,
-					  const char **fmtp_extra,
-					  struct mgcp_conn_rtp *conn)
-{
-	LOGPENDP(endp, DRTP, LOGL_DEBUG, "conn:%s using format defaults\n",
-		 mgcp_conn_dump(conn->conn));
-
-	*codec = conn->end.codec;
-	*fmtp_extra = conn->end.fmtp_extra;
-}
-
 void mgcp_rtp_annex_count(const struct mgcp_endpoint *endp,
 			  struct mgcp_rtp_state *state, const uint16_t seq,
 			  const int32_t transit, const uint32_t ssrc,
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index 809622b..2249a98 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -1712,8 +1712,6 @@
 	cfg->rtp_processing_cb = &mgcp_rtp_processing_default;
 	cfg->setup_rtp_processing_cb = &mgcp_setup_rtp_processing_default;
 
-	cfg->get_net_downlink_format_cb = &mgcp_get_net_downlink_format_default;
-
 	INIT_LLIST_HEAD(&cfg->trunks);
 
 	/* Allocate virtual trunk */
diff --git a/src/libosmo-mgcp/mgcp_sdp.c b/src/libosmo-mgcp/mgcp_sdp.c
index 10822e5..183c4ec 100644
--- a/src/libosmo-mgcp/mgcp_sdp.c
+++ b/src/libosmo-mgcp/mgcp_sdp.c
@@ -574,10 +574,8 @@
 	OSMO_ASSERT(sdp);
 	OSMO_ASSERT(addr);
 
-	/* FIXME: constify endp and conn args in get_net_donwlink_format_cb() */
-	endp->trunk->cfg->get_net_downlink_format_cb((struct mgcp_endpoint *)endp,
-					      &codec, &fmtp_extra,
-					      (struct mgcp_conn_rtp *)conn);
+	codec = conn->end.codec;
+	fmtp_extra = conn->end.fmtp_extra;
 
 	audio_name = codec->audio_name;
 	payload_type = codec->payload_type;