NFSd: Remove 'inline' designation for free_client()

It is large, it is used in more than one place, and it is not performance
critical. Let gcc figure out whether it should be inlined...

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>