Engine: Fix a bug introduced with voxel caching in fa3d6784

The texturecache file shouldn't be affected I think

source/build/src/texcache.cpp

@@ -922,7 +922,7 @@ voxmodel_t* voxcache_fetchvoxmodel(const char* const cacheid)
 
     voxcachedat_t voxd = {};
     size_t vertexsize, indexsize, mytexsize, totalsize;
-    voxmodel_t* vm = (voxmodel_t*)Xmalloc(sizeof(voxmodel_t));
+    voxmodel_t* vm = (voxmodel_t*)Xcalloc(1, sizeof(voxmodel_t));
 
     texcache.dataFilePos = texcache.entries[i]->offset;
     texcache_readdata(&voxd, sizeof(voxd));

source/build/src/voxmodel.cpp

@@ -435,8 +435,7 @@ void voxvbofree(voxmodel_t *vm)
 
 static voxmodel_t *vox2poly()
 {
-    gvox = (voxmodel_t *)Xmalloc(sizeof(voxmodel_t));
-    memset(gvox, 0, sizeof(voxmodel_t));
+    gvox = (voxmodel_t *)Xcalloc(1, sizeof(voxmodel_t));
 
     //x is largest dimension, y is 2nd largest dimension
     int32_t x = voxsiz.x, y = voxsiz.y, z = voxsiz.z;