nfs4: fix units bug causing hang on recovery

Note that cl_lease_time is in jiffies.  This can cause a very long wait
in the NFS4ERR_CLID_INUSE case.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>