crimson: drop the declared but undefined PG::do_osd_op().

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

src/crimson/osd/pg.h

@@ -536,10 +536,6 @@ private:
     ObjectContextRef obc,
     const OpInfo &op_info);
   seastar::future<Ref<MOSDOpReply>> do_pg_ops(Ref<MOSDOp> m);
-  seastar::future<> do_osd_op(
-    ObjectState& os,
-    OSDOp& op,
-    ceph::os::Transaction& txn);
   seastar::future<ceph::bufferlist> do_pgnls(ceph::bufferlist& indata,
 					     const std::string& nspace,
 					     uint64_t limit);