supervisor: change machine status to running after reimaging
supervisor: change machine status to running after reimaging

Signed-off-by: Shraddha Agrawal <01347c344ff9bfca8fb8f63951e1914d2ba7b87c@gmail.com>

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