test: fix addons/dlopen-ping-pong for npm 7.0.1

This partially reverts c87641a as node-gyp no longer
puts shared objects in an inconsistent location.

Author: MylesBorins

test/addons/dlopen-ping-pong/test.js

@@ -12,16 +12,8 @@ const bindingPath = require.resolve(`./build/${common.buildType}/binding`);
 console.log('process.dlopen:', bindingPath);
 process.dlopen(module, bindingPath,
                os.constants.dlopen.RTLD_NOW | os.constants.dlopen.RTLD_GLOBAL);
-
-let pingSOPath = `${path.dirname(bindingPath)}/lib.target/ping.so`;
-
-if (common.isOSX) {
-  pingSOPath = `${path.dirname(bindingPath)}/ping.so`;
-}
-
-console.log('module.exports.load:', pingSOPath);
-module.exports.load(pingSOPath);
-
+console.log('module.exports.load:', `${path.dirname(bindingPath)}/ping.so`);
+module.exports.load(`${path.dirname(bindingPath)}/ping.so`);
 assert.strictEqual(module.exports.ping(), 'pong');
 
 // Check that after the addon is loaded with