Remove useless and outright wrong chatter from avcodec_encode_video().

Originally committed as revision 18705 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/avcodec.h

@@ -3210,10 +3210,7 @@ int avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size,
 
 /**
  * Encodes a video frame from \p pict into \p buf.
- * The avcodec_encode_video() function encodes a video frame from the input
- * \p pict. To encode it, it makes use of the video codec which was coupled with
- * \p avctx using avcodec_open(). The resulting encoded bytes representing the
- * frame are stored in the output buffer \p buf. The input picture should be
+ * The input picture should be
  * stored using a specific format, namely \c avctx.pix_fmt.
  *
  * @param avctx the codec context