libavcodec/hqx: correct clipping error

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/hqx.c

@@ -182,7 +182,7 @@ static void hqx_idct_put(uint16_t *dst, ptrdiff_t stride,
 
     for (i = 0; i < 8; i++) {
         for (j = 0; j < 8; j++) {
-            int v = av_clip(block[j + i * 8] + 0x800, 0, 0x1000);
+            int v = av_clip(block[j + i * 8] + 0x800, 0, 0xFFF);
             dst[j] = (v << 4) | (v >> 8);
         }
         dst += stride >> 1;

tests/ref/fate/canopus-hqx422a

 #tb 0: 1/25
-0,          0,          0,        1,  8294400, 0x9b38264d
+0,          0,          0,        1,  8294400, 0x9a22bebf