Use new error variables when rolling back volume creation to avoid nil reassignment. (#617)
Use new error variables when rolling back volume creation to avoid nil reassignment. (#617)

This fix makes sure the original error message is delivered to docker, regardless of success/failure of error handling rollback actions. 
pshahzeb/vsphere-storage-for-docker,shuklanirdesh82/docker-volume-vsphere,pshahzeb/vsphere-storage-for-docker,luomiao/docker-volume-vsphere,brunotm/docker-volume-vsphere,pshahzeb/vsphere-storage-for-docker,ashahi1/docker-volume-vsphere,BaluDontu/docker-volume-vsphere,brunotm/docker-volume-vsphere,pshahzeb/vsphere-storage-for-docker,ashahi1/docker-volume-vsphere,BaluDontu/docker-volume-vsphere,ashahi1/docker-volume-vsphere,BaluDontu/docker-volume-vsphere,lipingxue/docker-volume-vsphere,venilnoronha/docker-volume-vsphere,shuklanirdesh82/docker-volume-vsphere,shivanshu21/docker-volume-vsphere,venilnoronha/docker-volume-vsphere,shuklanirdesh82/docker-volume-vsphere,govint/docker-volume-vsphere,govint/docker-volume-vsphere,lipingxue/docker-volume-vsphere,govint/docker-volume-vsphere,ashahi1/docker-volume-vsphere,brunotm/docker-volume-vsphere,BaluDontu/docker-volume-vsphere,govint/docker-volume-vsphere,lipingxue/docker-volume-vsphere,ashahi1/docker-volume-vsphere,venilnoronha/docker-volume-vsphere,shivanshu21/docker-volume-vsphere,luomiao/docker-volume-vsphere,shivanshu21/docker-volume-vsphere,venilnoronha/docker-volume-vsphere,venilnoronha/docker-volume-vsphere,lipingxue/docker-volume-vsphere,shivanshu21/docker-volume-vsphere,pshahzeb/vsphere-storage-for-docker,luomiao/docker-volume-vsphere,brunotm/docker-volume-vsphere,brunotm/docker-volume-vsphere,lipingxue/docker-volume-vsphere,BaluDontu/docker-volume-vsphere,venilnoronha/docker-volume-vsphere,lipingxue/docker-volume-vsphere,luomiao/docker-volume-vsphere,brunotm/docker-volume-vsphere,pshahzeb/vsphere-storage-for-docker,BaluDontu/docker-volume-vsphere,govint/docker-volume-vsphere,luomiao/docker-volume-vsphere,shivanshu21/docker-volume-vsphere,luomiao/docker-volume-vsphere,shuklanirdesh82/docker-volume-vsphere,shuklanirdesh82/docker-volume-vsphere,govint/docker-volume-vsphere,ashahi1/docker-volume-vsphere,shivanshu21/docker-volume-vsphere,BaluDontu/docker-volume-vsphere,shuklanirdesh82/docker-volume-vsphere