vfs-cache: do not use memoizeWithExpiration if cachelifetime is zero

ExpiringMemoizingSupplier uses zero as a special value

Acked-by: Albert Rossi
Target: master, 0.9
(cherry picked from commit 43868055bf7f475d89013d825ff0d0db769717ec)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
nfsv3: remove useless lookup and getattr on remove

Acked-by: Albert Rossi
Target: master, 0.9
(cherry picked from commit 73381984d8a7a2334390554e6a23479b60fcd016)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>