avcodec/dca_lbr: explicitly initialize structs with zero

This fixes build on MSVC and conforms to the usual init style used.

libavcodec/dca_lbr.c

@@ -1161,7 +1161,7 @@ int ff_dca_lbr_parse(DCALbrDecoder *s, uint8_t *data, DCAExssAsset *asset)
         LBRChunk    hr_grid[DCA_LBR_CHANNELS / 2];
         LBRChunk    ts1[DCA_LBR_CHANNELS / 2];
         LBRChunk    ts2[DCA_LBR_CHANNELS / 2];
-    } chunk = { };
+    } chunk = { 0 };
 
     GetByteContext gb;
 

libavcodec/dcadata.c

@@ -8830,7 +8830,7 @@ const uint8_t ff_dca_grid_1_weights[12][32] = {
           0,   0,   0,   0,   0,   0,   0,   0,
           0,  18,  37,  55,  73,  91, 110, 128,
     }, {
-        /* empty */
+        0 /* empty */
     }
 };