radv: Init variant entry with memset.

This gets memcpy'd and written driectly, and due to alignment, this
resulted in uninitialized gaps. This makes those gaps go away.

CC: <mesa-stable@lists.freedesktop.org>
Reviewed-by: Dave Airlie <airlied@redhat.com>

src/amd/vulkan/radv_pipeline_cache.c

@@ -380,6 +380,7 @@ radv_pipeline_cache_insert_shaders(struct radv_device *device,
 
 	char* p = entry->code;
 	struct cache_entry_variant_info info;
+	memset(&info, 0, sizeof(info));
 
 	for (int i = 0; i < MESA_SHADER_STAGES; ++i) {
 		if (!variants[i])