Consolidate removal of Suspect or Evacuating instances
Consolidate removal of Suspect or Evacuating instances

Removes duplicate logic in evacuation controller methods

Signed-off-by: Sunjay Bhatia <df2d57be7987a471915f625a5499155bc16d4200@pivotal.io>

cloudfoundry-incubator/bbs,cloudfoundry-incubator/bbs