avcodec/mpeg12dec: remove outdated comments

Found-by: Kieran
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 48de8f5816aa54dc584aeb2dbbf63a0e880279e2)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/mpeg12dec.c

@@ -221,7 +221,6 @@ end:
 }
 
 /**
- * Note: this function can read out of range and crash for corrupt streams.
  * Changing this would eat up any speed benefits it has.
  * Do not use "fast" flag if you need the code to be robust.
  */
@@ -397,7 +396,6 @@ end:
 }
 
 /**
- * Note: this function can read out of range and crash for corrupt streams.
  * Changing this would eat up any speed benefits it has.
  * Do not use "fast" flag if you need the code to be robust.
  */
@@ -559,7 +557,6 @@ static inline int mpeg2_decode_block_intra(MpegEncContext *s,
 }
 
 /**
- * Note: this function can read out of range and crash for corrupt streams.
  * Changing this would eat up any speed benefits it has.
  * Do not use "fast" flag if you need the code to be robust.
  */