record: use vlc_MakeTmpFile (thus mkstemp) instead of tempnam

resolves warning about insecure function

modules/stream_out/record.c

@@ -463,14 +463,16 @@ static void OutputStart( sout_stream_t *p_stream )
         for( unsigned i = 0; i < sizeof(ppsz_muxers) / sizeof(*ppsz_muxers); i++ )
         {
             char *psz_file;
-            int i_es;
-
-            psz_file = tempnam( NULL, "vlc" );
-            if( !psz_file )
+            int fd = vlc_MakeTmpFile(&psz_file, PACKAGE_NAME"-rec.XXXXXX", NULL);
+            if( fd == -1 )
+            {
+                msg_Warn( p_stream, "failed to create temporary file" );
                 continue;
+            }
 
             msg_Dbg( p_stream, "probing muxer %s", ppsz_muxers[i][0] );
-            i_es = OutputNew( p_stream, ppsz_muxers[i][0], psz_file, NULL );
+            int i_es = OutputNew( p_stream, ppsz_muxers[i][0], psz_file, NULL );
+            vlc_close( fd );
 
             if( i_es < 0 )
             {