Feature gate test benchmark_storage_works

tests/benchmark_storage_works.rs

@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
 
+#![cfg(feature = "runtime-benchmarks")]
+
 use assert_cmd::cargo::cargo_bin;
 use std::{
 	path::Path,