mkv: Avoid duplicating the entire vector.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/demux/mkv/virtual_segment.cpp

@@ -263,7 +263,7 @@ chapter_item_c *virtual_segment_c::FindChapter( int64_t i_find_uid )
     return NULL;
 }
 
-void virtual_segment_c::AddSegments(std::vector<matroska_segment_c *> segments)
+void virtual_segment_c::AddSegments( const std::vector<matroska_segment_c *> &segments)
 {
     // fill our current virtual segment with all hard linked segments
     size_t i_preloaded;

modules/demux/mkv/virtual_segment.hpp

@@ -49,7 +49,7 @@ public:
         AppendUID( p_segment->p_next_segment_uid );
     }
 
-    void AddSegments( std::vector<matroska_segment_c*> segments );
+    void AddSegments( const std::vector<matroska_segment_c*> &segments );
 
     void Seek( demux_t & demuxer, mtime_t i_date, mtime_t i_time_offset, chapter_item_c *p_chapter, int64_t i_global_position );