nfsd: don't take/put an extra reference when putting a file

[ Upstream commit b2ff1bd7 ]

The last thing that filp_close does is an fput, so don't bother taking
and putting the extra reference.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>