crimson/osd: std::move func in pg::with_*_obc().

crimson/osd: std::move func in pg::with_*_obc().

Well, likely all the commit does is just appending a couple
of extra bytes. Though, strictly juding, a func should be
`std::move()`d before calling in those cases. Otherwise we
can miss e.g. the `operator() &&` overload.

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>