engine : if setSucceeded(true) is called before exception command is presented as succeeded

if any Command calls: getReturnValue().setSucceeded(true);
and after that follows some logic, then if this logic
fails, outcome of this command will be presented as
successful. Compensation/rollbacks etc. are called, but
data sent to user is wrong.

Change-Id: Iee7b186314dacdeeb818c6fdf5157876b0b8342e
Bug-Url: https://bugzilla.redhat.com/1106464
Signed-off-by: Ravi Nori <rnori@redhat.com>