avcodec/dvdec: Make dv_iweight_720_c static

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

libavcodec/dvdec.c

@@ -116,7 +116,7 @@ static const uint16_t dv_iweight_720_y[64] = {
      96,  98,  96,  88,  96,  98, 202, 196,
     196, 202, 208, 218, 208, 232, 232, 246,
 };
-const uint16_t dv_iweight_720_c[64] = {
+static const uint16_t dv_iweight_720_c[64] = {
     128,  24,  24,  26,  26,  26,  36,  36,
      36,  36,  36,  36,  38,  36,  36,  38,
      38,  38,  38,  38,  38,  84,  76,  80,