fix drv.cc invalid output throw

EvalState::error does not return an exception instance in lix, but an
exception *builder*. throwing this thing will not trigger any catches,
which then causes the worker process to die without reporting an error
to the collector. this confuses the collector and causes *it* to exit,
effectively breaking nix-eval-jobs for anything that has broken attrs.

src/drv.cc

@@ -50,7 +50,8 @@ Drv::Drv(std::string &attrPath, nix::EvalState &state, nix::DrvInfo &drvInfo,
                 outputs[out.first] = localStore->printStorePath(*out.second);
         }
     } catch (const std::exception &e) {
-        throw state.error<nix::EvalError>("derivation '%s' does not have valid outputs: %s",
+        throw nix::EvalError(state,
+            "derivation '%s' does not have valid outputs: %s",
             attrPath, e.what());
     }