osd/ReplicatedPG: fix reversed issue_repop temp object check

We want to ship an empty txn if the pool *does* match; if it doesn't, we
always ship the full thing (because it is a temp object).  This was
reversed in commit e10ee61fb66a11324aa176630d676a6a95ee572a

Signed-off-by: Sage Weil <sage@inktank.com>