smb: client: do not start laundromat thread on nohandlecache

Honor 'nohandlecache' mount option by not starting laundromat thread
even when SMB server supports directory leases. Do not waste system
resources by having laundromat thread running with no directory
caching at all.

Fixes: 2da338ff

 ("smb3: do not start laundromat thread when dir leases  disabled")
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>