Change type of zz_table to uint8_t to match the scantables it points to.

Originally committed as revision 23831 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/vc1dec.c

@@ -1481,7 +1481,7 @@ static int vc1_decode_i_block(VC1Context *v, DCTELEM block[64], int n, int coded
 
     {
         int last = 0, skip, value;
-        const int8_t *zz_table;
+        const uint8_t *zz_table;
         int scale;
         int k;
 
@@ -1667,7 +1667,7 @@ static int vc1_decode_i_block_adv(VC1Context *v, DCTELEM block[64], int n, int c
 
     if(coded) {
         int last = 0, skip, value;
-        const int8_t *zz_table;
+        const uint8_t *zz_table;
         int k;
 
         if(v->s.ac_pred) {
@@ -1874,7 +1874,7 @@ static int vc1_decode_intra_block(VC1Context *v, DCTELEM block[64], int n, int c
 
     if(coded) {
         int last = 0, skip, value;
-        const int8_t *zz_table;
+        const uint8_t *zz_table;
         int k;
 
         zz_table = wmv1_scantable[0];