Address clippy warning

src/utils.rs

@@ -67,6 +67,6 @@ impl VariableDeclarationStack
 	pub fn pop(&mut self) -> Result<(), crate::Error>
 	{
 		self.bound_variable_declaration_stack.pop().map(|_| ())
-			.ok_or(crate::Error::new_logic("variable stack not in expected state"))
+			.ok_or_else(|| crate::Error::new_logic("variable stack not in expected state"))
 	}
 }