avcodec/prosumer: Simplify bit juggling of the c variable in decompress()

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/prosumer.c

@@ -69,15 +69,13 @@ static int decompress(GetByteContext *gb, int size, PutByteContext *pb, const ui
             }
             c = b >> 16;
             if (c & 0xFF00u) {
-                c = (((c >> 8) & 0xFFu) | (c & 0xFF00)) & 0xF00F;
                 fill = lut[2 * idx + 1];
-                if ((c & 0xFF00u) == 0x1000) {
+                if ((c & 0xF000u) == 0x1000) {
                     bytestream2_put_le16(pb, fill);
-                    c &= 0xFFFF00FFu;
                 } else {
                     bytestream2_put_le32(pb, fill);
-                    c &= 0xFFFF00FFu;
                 }
+                c = (c >> 8) & 0x0Fu;
             }
             while (c) {
                 a <<= 4;