logging failed exception info for add image operation
logging failed exception info for add image operation

Add image operation failed will lead to rollback operation,
delete this image if it was created.
If this operation throws some exception, previous one will be
overwritten so that we cannot elegantly trace the problem occurs.
We could log failed exception info before rollback operation.

Change-Id: Ic26a63f760d103a561cd4766b7497b34a0b14fc1
modified:   glance_store/_drivers/rbd.py

cpallares/glance_store,openstack/glance_store,cpallares/glance_store,redhat-openstack/glance_store,openstack/glance_store,redhat-openstack/glance_store