100l, fix MS ADPCM decoding for e.g. http://samples.mplayerhq.hu/mov/qtaudio/surge-2-16-L-ms02.mov

First coefficient array must be unsigned to fit in 8 bits

Originally committed as revision 14175 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/adpcm.c

@@ -85,7 +85,7 @@ static const int AdaptationTable[] = {
         768, 614, 512, 409, 307, 230, 230, 230
 };
 
-static const int8_t AdaptCoeff1[] = {
+static const uint8_t AdaptCoeff1[] = {
         64, 128, 0, 48, 60, 115, 98
 };