rgw/multisite: avoid redundant error repo entry logging

in bucket incremental sync, if a generation other than the current generation is requested,
we mark it with -EAGAIN and retry in error repo in RGWDataSyncSingleEntry(). within this block,
we check if that requested generation is lesser than the current gen, write it to error repo,
set -EAGAIN and write it to error repo in the outer function once again. don't duplicate error
repo entry addition for this condition.

Signed-off-by: Shilpa Jagannath <[email protected]>

Author: Shilpa Jagannath

src/rgw/driver/rados/rgw_data_sync.cc

@@ -6044,12 +6044,13 @@ int RGWSyncBucketCR::operate(const DoutPrefixProvider *dpp)
               } else {
                 tn->log(20, SSTR("logged prev gen entry (bucket=" << source_bs.bucket << ", shard_id=" << source_bs.shard_id << ", gen=" << current_gen << " in error repo: retcode=" << retcode));
 	      }
-	    }
+	    } else {
             retcode = -EAGAIN;
             tn->log(10, SSTR("ERROR: requested sync of future generation "
                              << *gen << " > " << current_gen
                              << ", returning " << retcode << " for later retry"));
             return set_cr_error(retcode);
+            }
           } else if (*gen < current_gen) {
             tn->log(10, SSTR("WARNING: requested sync of past generation "
                              << *gen << " < " << current_gen