stream_out/autodel.c: check malloc return value

If allocating fails, then graciously fail instead of crash.

modules/stream_out/autodel.c

@@ -81,6 +81,8 @@ static int Open( vlc_object_t *p_this )
     sout_stream_sys_t *p_sys;
 
     p_sys          = malloc( sizeof( sout_stream_sys_t ) );
+    if( !p_sys )
+        return VLC_ENOMEM;
 
     if( !p_stream->p_next )
     {
@@ -120,6 +122,8 @@ static sout_stream_id_t * Add( sout_stream_t *p_stream, es_format_t *p_fmt )
 {
     sout_stream_sys_t *p_sys = (sout_stream_sys_t *)p_stream->p_sys;
     sout_stream_id_t *p_es = malloc( sizeof(sout_stream_id_t) );
+    if( !p_es )
+        return NULL;
 
     p_es->fmt = *p_fmt;
     p_es->id = NULL;