Fix misc warnings in demuxers

modules/demux/nsc.c

@@ -296,6 +296,7 @@ static int DemuxOpen( vlc_object_t * p_this )
  *****************************************************************************/
 static void DemuxClose( vlc_object_t *p_this )
 {
+    VLC_UNUSED( p_this );
     return;
 }
 
@@ -362,5 +363,7 @@ static int Demux ( demux_t *p_demux )
 
 static int Control( demux_t *p_demux, int i_query, va_list args )
 {
+    VLC_UNUSED( p_demux ); VLC_UNUSED( i_query ); VLC_UNUSED( args );
+    //FIXME
     return VLC_EGENERIC;
 }

modules/demux/pva.c

@@ -378,7 +378,7 @@ static void ParsePES( demux_t *p_demux )
     uint8_t     hdr[30];
     int         i_pes_size;
 
-    int         i_skip;
+    unsigned    i_skip;
     mtime_t     i_dts = -1;
     mtime_t     i_pts = -1;