refactor error summary logic so it can be reused
refactor error summary logic so it can be reused

Change-Id: Ia5e55c035d087a27fa824f60a3a8aef19f6d485b
Signed-off-by: Doug Hellmann <0798ebecfb7bc4dfb9d0445c2fa030eb64e1fa1c@doughellmann.com>

openstack/oslo.log