#### Is your feature request related to a problem? Please describe.
This is an optimazition of code.

#### Describe the solution you'd like
The following line of code comes from https://github.com/axios/axios/blob/master/lib/adapters/http.js#L403:
```js
reject(!cancel || (cancel && cancel.type) ? new CanceledError() : cancel);
```
It can be optimized as follows:
```js
reject(!cancel || cancel.type ? new CanceledError() : cancel);
```

#### Describe alternatives you've considered
When the code is executed to `(cancel && cancel.type)`, it means `!cancel` is false, so `cancel` is true, we can get `cancel.type` directly.

#### Additional context
no more

lib/adapters/xhr.js
if (!request) {
        return;
      }
      
      var responseHeaders = 'getAllResponseHeaders' in request ? parseHeaders(request.getAllResponseHeaders()) : null;
      var responseData = !responseType || responseType === 'text' ||  responseType === 'json' ?
        request.responseText : request.response;
      var response = {
        data: responseData,
        status: request.status,
        statusText: request.statusText,
        headers: responseHeaders,
        config: config,
        request: request
      };
      settle(function _resolve(value) {
        resolve(value);
        done();
      }, function _reject(err) {
        reject(err);
        done();
      }, response);
      
      request = null;
    }
    if ('onloadend' in request) {