avfilter/af_hdcd: Use int32_t instead of int for gaintable in hdcd filter.

Signed-off-by: Benjamin Steffes <benjaminst123@gmail.com>

(comment by ronald)
prevent the theoretical case where the container type (int)
would be 64 bit on some platforms, which would waste some space
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavfilter/af_hdcd.c

@@ -683,7 +683,7 @@ static const uint8_t readaheadtab[] = {
 };
 
 //values between 0 and 1 multiplied by 2^23 to avoid floating point numbers.
-static const int gaintab[] = {
+static const int32_t gaintab[] = {
     0x800000, 0x7ff144, 0x7fe28a, 0x7fd3d2, 0x7fc51b, 0x7fb666, 0x7fa7b3, 0x7f9901, 0x7f8a52, 0x7f7ba3, 0x7f6cf7, 0x7f5e4c, 0x7f4fa3, 0x7f40fc, 0x7f3256,
     0x7f23b2, 0x7f1510, 0x7f066f, 0x7ef7d0, 0x7ee933, 0x7eda97, 0x7ecbfd, 0x7ebd65, 0x7eaece, 0x7ea039, 0x7e91a6, 0x7e8315, 0x7e7485, 0x7e65f6, 0x7e576a,
     0x7e48df, 0x7e3a56, 0x7e2bce, 0x7e1d49, 0x7e0ec5, 0x7e0042, 0x7df1c1, 0x7de342, 0x7dd4c5, 0x7dc649, 0x7db7cf, 0x7da956, 0x7d9adf, 0x7d8c6a, 0x7d7df7,