If p9_client_lock_dotl returns an error, status is possibly never filled
but will be used in the following switch.
Initializing it to P9_LOCK_ERROR makes sur we will return an error and
cleanup (and not hit the default case).
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>