Fix error when trying to run --remove-all

The error was as follows:

sudo hose --remove-all

/usr/local/share/npm/lib/node_modules/hose/index.js:32
        if (!err) {
             ^
ReferenceError: err is not defined
    at /usr/local/share/npm/lib/node_modules/hose/index.js:32:14
    at Object.oncomplete (fs.js:107:15)