avcodec/vqcdec: Check init_get_bits8() for failure

Fixes: CID1516090 Unchecked return value

Sponsored-by: Sovereign Tech Fund
Reviewed-by: Peter Ross <pross@xvid.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 6a9302739f)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/vqcdec.c

@@ -146,10 +146,13 @@ static int decode_vectors(VqcContext * s, const uint8_t * buf, int size, int wid
     GetBitContext gb;
     uint8_t * vectors = s->vectors;
     uint8_t * vectors_end = s->vectors + (width * height * 3) / 2;
+    int ret;
 
     memset(vectors, 0, 3 * width * height / 2);
 
-    init_get_bits8(&gb, buf, size);
+    ret = init_get_bits8(&gb, buf, size);
+    if (ret < 0)
+        return ret;
 
     for (int i = 0; i < 3 * width * height / 2 / 32; i++) {
         uint8_t * dst = vectors;