drivers: staging: lustre: Cleanup src/dst comparisons in obdo_cmp_md()

Cleanup obdo_cmp_md() src/dst comparisons using bitwise OR assignments

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Donald <gdonald@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>