nfsd: Fix memleak

commit 2d32b29a1c2830f7c42caa8258c714acd983961f upstream.

When free nfs-client, it must free the ->cl_stateids.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>