rgw_sal_motr: [CORTX-32697] support user remove with purge data

During Remove User code-flow till the DeleteOp is instantiated for
each obj from a bucket, we don't have the access to req_state ptr
via RGWObjectCtx. This causes the addb.set_id(rctx) to fail, as it
tries to access the req_id from null req_state ptr.
To avoid the situation, guarded the addb.set_id() call by checking
if we have the req_state ptr accesible.

Signed-off-by: Sumedh Anantrao Kulkarni <sumedh.a.kulkarni@seagate.com>

src/rgw/rgw_sal_motr.cc

@@ -2071,7 +2071,11 @@ MotrObject::MotrDeleteOp::MotrDeleteOp(MotrObject *_source, RGWObjectCtx *_rctx)
   source(_source),
   rctx(_rctx)
 {
-  addb_logger.set_id(rctx);
+  // In case of the operation remove_user with --purge-data, we don't 
+  // have access to the `req_state* s` via `RGWObjectCtx* rctx`.
+  // In this case ,the req_id for addb_logger will have a default value.
+  if (rctx->get_private())
+    addb_logger.set_id(rctx);
 }
 
 // Implementation of DELETE OBJ also requires MotrObject::get_obj_state()