golomb: fix end of bitstream check

Fixes Ticket806
Bug found by Oana Stratulat
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/golomb.h

@@ -302,7 +302,7 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int
     }else{
         int i;
         for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
-            if (get_bits_left(gb)<=0)
+            if (gb->size_in_bits <= re_index)
                 return -1;
             LAST_SKIP_BITS(re, gb, 1);
             UPDATE_CACHE(re, gb);