engine : Suspend VM fails with a NullPointerException

Suspending a VM when Async Tasks with no
entityInfo set in parameters are being executed
throws a NPE

Change-Id: I75a807af67c8f6683f2023fe37f7847ef0aa2eb5
Bug-Url: https://bugzilla.redhat.com/1160876
Signed-off-by: Ravi Nori <rnori@redhat.com>