Fix crash for CAVLC->CABAC switch caused by writing into NULL tables.

(iam not sure if this might have been exploitable)
fixes issue332 / CVCANLMA2_Sony_C.jsv
Other solutions which waste a few bytes less are welcome ...

Originally committed as revision 11605 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -2035,12 +2035,10 @@ static int alloc_tables(H264Context *h){
     CHECKED_ALLOCZ(h->slice_table_base  , (big_mb_num+s->mb_stride) * sizeof(uint8_t))
     CHECKED_ALLOCZ(h->cbp_table, big_mb_num * sizeof(uint16_t))
 
-    if( h->pps.cabac ) {
         CHECKED_ALLOCZ(h->chroma_pred_mode_table, big_mb_num * sizeof(uint8_t))
         CHECKED_ALLOCZ(h->mvd_table[0], 32*big_mb_num * sizeof(uint16_t));
         CHECKED_ALLOCZ(h->mvd_table[1], 32*big_mb_num * sizeof(uint16_t));
         CHECKED_ALLOCZ(h->direct_table, 32*big_mb_num * sizeof(uint8_t));
-    }
 
     memset(h->slice_table_base, -1, (big_mb_num+s->mb_stride)  * sizeof(uint8_t));
     h->slice_table= h->slice_table_base + s->mb_stride*2 + 1;