os: throw when os.networkInterfaces() fails

src/node_os.cc

@@ -206,9 +206,8 @@ static Handle<Value> GetInterfaceAddresses(const Arguments& args) {
 
   uv_err_t err = uv_interface_addresses(&interfaces, &count);
 
-  if (err.code != UV_OK) {
+  if (err.code != UV_OK)
-    return Undefined();
+    return ThrowException(UVException(err.code, "uv_interface_addresses"));
-  }
 
   ret = Object::New();