orchestra.run: Fix bug in RemoteProcess.finished
orchestra.run: Fix bug in RemoteProcess.finished

Previously, if wait() had not been called, we didn't have the returncode
attribute set. Set it from within the finished property if it isn't
already.

Signed-off-by: Zack Cerza <d7cdf09fc0f0426e98c9978ee42da5d61fa54986@redhat.com>

SUSE/teuthology,dmick/teuthology,SUSE/teuthology,ktdreyer/teuthology,SUSE/teuthology,dmick/teuthology,ceph/teuthology,ceph/teuthology,dmick/teuthology,ktdreyer/teuthology