r/recovery_stm: stop recovery when follower was already updated

Recovery and replicate stms are not synchronized. It may be the case
when both of stms are active at the same time that the same batch is
delivered to the follower twice. In general this batch duplication is
harmless as Raft is not vulnerable for messages redelivery but it may
cause unnecessary truncation and latency increase.

Added a check validating expected log end offset right before sending
recovery append entries request. This will prevent sending the same set
of batches twice to the follower.

Fixes: #14413

Signed-off-by: Michal Maslanka <michal@redpanda.com>

src/v/raft/recovery_stm.cc

@@ -557,6 +557,18 @@ ss::future<> recovery_stm::replicate(
         _stop_requested = true;
         return ss::now();
     }
+    if (meta.value()->expected_log_end_offset >= _last_batch_offset) {
+        vlog(
+          _ctxlog.trace,
+          "follower expected log end offset is already updated, stopping "
+          "recovery. Expected log end offset: {}, recovery range last offset: "
+          "{}",
+          meta.value()->expected_log_end_offset,
+          _last_batch_offset);
+
+        _stop_requested = true;
+        return ss::now();
+    }
     /**
      * Update follower expected log end. It is equal to the last batch in a set
      * of batches read for this recovery round.