rtspsrc: Properly error out if binding the UDP sockets fails

udpsrc is not returning us a socket in that case.

gst/rtsp/gstrtspsrc.c

@@ -3545,6 +3545,9 @@ gst_rtspsrc_stream_configure_udp_sinks (GstRTSPSrc * src,
       /* configure socket, we give it the same UDP socket as the udpsrc for RTP
        * so that NAT firewalls will open a hole for us */
       g_object_get (G_OBJECT (stream->udpsrc[0]), "used-socket", &socket, NULL);
+      if (!socket)
+        goto no_socket;
+
       GST_DEBUG_OBJECT (src, "RTP UDP src has sock %p", socket);
       /* configure socket and make sure udpsink does not close it when shutting
        * down, it belongs to udpsrc after all. */
@@ -3600,6 +3603,9 @@ gst_rtspsrc_stream_configure_udp_sinks (GstRTSPSrc * src,
        * because some servers check the port number of where it sends RTCP to identify
        * the RTCP packets it receives */
       g_object_get (G_OBJECT (stream->udpsrc[1]), "used-socket", &socket, NULL);
+      if (!socket)
+        goto no_socket;
+
       GST_DEBUG_OBJECT (src, "RTCP UDP src has sock %p", socket);
       /* configure socket and make sure udpsink does not close it when shutting
        * down, it belongs to udpsrc after all. */
@@ -3637,17 +3643,22 @@ gst_rtspsrc_stream_configure_udp_sinks (GstRTSPSrc * src,
   /* ERRORS */
 no_destination:
   {
-    GST_DEBUG_OBJECT (src, "no destination address specified");
+    GST_ERROR_OBJECT (src, "no destination address specified");
     return FALSE;
   }
 no_sink_element:
   {
-    GST_DEBUG_OBJECT (src, "no UDP sink element found");
+    GST_ERROR_OBJECT (src, "no UDP sink element found");
     return FALSE;
   }
 no_fakesrc_element:
   {
-    GST_DEBUG_OBJECT (src, "no fakesrc element found");
+    GST_ERROR_OBJECT (src, "no fakesrc element found");
+    return FALSE;
+  }
+no_socket:
+  {
+    GST_ERROR_OBJECT (src, "failed to create socket");
     return FALSE;
   }
 }