staging: lustre: lov: Cleanup lov_check_set() in lov_request.c

Make the code clearer by introducing a local variable and removing the
unnecessary 'if' statement.

Signed-off-by: Riccardo Lucchese <riccardo.lucchese@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>