avcodec/vp3: Fix "runtime error: left shift of negative value"

Fixes: 5c6129154b356b80bcab86f9e3ee5d29/signal_sigabrt_7ffff6ae7cc9_7322_d26ac6d7cb6567db1b8be0159b387d0b.ogg

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/vp3.c

@@ -209,8 +209,8 @@ typedef struct Vp3DecodeContext {
     int16_t *dct_tokens[3][64];
     int16_t *dct_tokens_base;
 #define TOKEN_EOB(eob_run)              ((eob_run) << 2)
-#define TOKEN_ZERO_RUN(coeff, zero_run) (((coeff) << 9) + ((zero_run) << 2) + 1)
+#define TOKEN_ZERO_RUN(coeff, zero_run) (((coeff) * 512) + ((zero_run) << 2) + 1)
-#define TOKEN_COEFF(coeff)              (((coeff) << 2) + 2)
+#define TOKEN_COEFF(coeff)              (((coeff) * 4) + 2)
 
     /**
      * number of blocks that contain DCT coefficients at