errors: simplify sysError

lib/internal/errors.js

@@ -842,7 +842,7 @@ E('ERR_STREAM_UNSHIFT_AFTER_END_EVENT',
   'stream.unshift() after end event', Error);
 E('ERR_STREAM_WRAP', 'Stream has StringDecoder set or is in objectMode', Error);
 E('ERR_STREAM_WRITE_AFTER_END', 'write after end', Error);
-E('ERR_SYSTEM_ERROR', sysError('A system error occurred'));
+E('ERR_SYSTEM_ERROR', sysError);
 E('ERR_TLS_CERT_ALTNAME_INVALID',
   'Hostname/IP does not match certificate\'s altnames: %s', Error);
 E('ERR_TLS_DH_PARAM_SIZE', 'DH parameter size %s is less than 2048', Error);
@@ -903,26 +903,21 @@ E('ERR_VM_MODULE_STATUS', 'Module status %s', Error);
 E('ERR_ZLIB_BINDING_CLOSED', 'zlib binding closed', Error);
 E('ERR_ZLIB_INITIALIZATION_FAILED', 'Initialization failed', Error);
 
-function sysError(defaultMessage) {
-  return function(code,
-                  syscall,
-                  path,
-                  dest,
-                  message = defaultMessage) {
-    if (code !== undefined)
-      message += `: ${code}`;
-    if (syscall !== undefined) {
-      if (code === undefined)
-        message += ':';
-      message += ` [${syscall}]`;
-    }
-    if (path !== undefined) {
-      message += `: ${path}`;
-      if (dest !== undefined)
-        message += ` => ${dest}`;
-    }
-    return message;
-  };
+function sysError(code, syscall, path, dest,
+                  message = 'A system error occurred') {
+  if (code !== undefined)
+    message += `: ${code}`;
+  if (syscall !== undefined) {
+    if (code === undefined)
+      message += ':';
+    message += ` [${syscall}]`;
+  }
+  if (path !== undefined) {
+    message += `: ${path}`;
+    if (dest !== undefined)
+      message += ` => ${dest}`;
+  }
+  return message;
 }
 
 function invalidArgType(name, expected, actual) {