fs: Remove unused branches

In a few places the code was refactored to use `maybeCallback` which always returns a function. Checking for `if (callback)` always returns true anyway. PR-URL: #4795 Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: thefourtheye <thechargingvolcano@gmail.com>

Author: benjamingr

lib/fs.js

@@ -1160,16 +1160,16 @@ function writeAll(fd, isUserFd, buffer, offset, length, position, callback_) {
  fs.write(fd, buffer, offset, length, position, function(writeErr, written) {
  if (writeErr) {
  if (isUserFd) {
- if (callback) callback(writeErr);
+ callback(writeErr);
  } else {
  fs.close(fd, function() {
- if (callback) callback(writeErr);
+ callback(writeErr);
  });
  }
  } else {
  if (written === length) {
  if (isUserFd) {
- if (callback) callback(null);
+ callback(null);
  } else {
  fs.close(fd, callback);
  }
@@ -1207,7 +1207,7 @@ fs.writeFile = function(path, data, options, callback_) {
 
  fs.open(path, flag, options.mode, function(openErr, fd) {
  if (openErr) {
- if (callback) callback(openErr);
+ callback(openErr);
  } else {
  writeFd(fd, false);
  }