Fix reference to a file in MPlayer that was renamed.

Originally committed as revision 12770 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/rtjpeg.c

@@ -41,7 +41,7 @@
  *
  * Note: GetBitContext is used to make the code simpler, since all data is
  * aligned this could be done faster in a different way, e.g. as it is done
- * in MPlayer libmpcodecs/native/RTjpegN.c
+ * in MPlayer libmpcodecs/native/rtjpegn.c.
  */
 static inline int get_block(GetBitContext *gb, DCTELEM *block, const uint8_t *scan,
                             const uint32_t *quant) {