Hi all I am trying to bug fix. but, I failed to request code review like below

'

# git review <br>
remote: Resolving deltas: 100% (6/6)
remote: Processing changes: refs: 1, done

To ssh://Hahyun@review.openstack.org:29418/openstack/cinder.git ! [remote rejected] HEAD -> refs/publish/master/bug/1433450 (you are not allowed to upload merges) error: failed to push some refs to 'ssh://Hahyun@review.openstack.org:29418/openstack/cinder.git

I have launchpad id, gerrit username, github username etc..

My steps are below:
1) git clone
2) cd cinder
3) git review -s
4) git checkout -b bug/1437794
5) change the code
6) git add [changed file]
7) git commit -a
8) git review

What should I do for bug fix? I cannot understand why "git review" was failed. please someone help me.

thanks in advance.