avcodec/golomb: Document return for get_ur_golomb_jpegls() and get_sr_golomb_flac()

Found while reviewing code related to CID1604409 Overflowed return value

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/golomb.h

@@ -424,6 +424,8 @@ static inline int get_ur_golomb(GetBitContext *gb, int k, int limit,
 
 /**
  * read unsigned golomb rice code (jpegls).
+ *
+ * @returns -1 on error
  */
 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
                                        int esc_len)
@@ -535,6 +537,8 @@ static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
 
 /**
  * read signed golomb rice code (flac).
+ *
+ * @returns INT_MIN on error
  */
 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit,
                                      int esc_len)