Defer close only when lease is enabled.

When smb2 lease parameter is disabled on server. Server grants
batch oplock instead of RHW lease by default on open, inode page cache
needs to be zapped immediatley upon close as cache is not valid.

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>