Cleanup missing frees on some ioctls

commit 24df1483c272c99ed88b0cba135d0e1dfdee3930 upstream.

Cleanup some missing mem frees on some cifs ioctls, and
clarify others to make more obvious that no data is returned.

Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>