rlc_um: reduce log level for message handling lost PDUs

when a lost PDU is detected a warning will be logged. In theory
this could be info as well but a warning may help to detect issues
in tests. The same event causes multiple other warnings to be logged,
which is very spammy. The patch reduces the log level for
those messages to info.

lib/src/upper/rlc_um_lte.cc

@@ -478,8 +478,7 @@ void rlc_um_lte::rlc_um_lte_rx::reassemble_rx_sdus()
     logger.debug("Reassemble loop for vr_ur=%d", vr_ur);
 
     if (not pdu_belongs_to_rx_sdu()) {
-      logger.warning(
-          "PDU SN=%d lost, stop reassambling SDU (vr_ur_in_rx_sdu=%d)", vr_ur_in_rx_sdu + 1, vr_ur_in_rx_sdu);
+      logger.info("PDU SN=%d lost, stop reassambling SDU (vr_ur_in_rx_sdu=%d)", vr_ur_in_rx_sdu + 1, vr_ur_in_rx_sdu);
       pdu_lost = false; // Reset flag to not prevent reassembling of further segments
       rx_sdu->clear();
     }
@@ -495,7 +494,7 @@ void rlc_um_lte::rlc_um_lte_rx::reassemble_rx_sdus()
                    rlc_fi_field_text[rx_window[vr_ur].header.fi]);
       // Check if the first part of the PDU is a middle or end segment
       if (rx_sdu->N_bytes == 0 && i == 0 && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
-        logger.warning(
+        logger.info(
             rx_window[vr_ur].buf->msg, len, "Dropping first %d B of SN=%d due to lost start segment", len, vr_ur);
 
         if (rx_window[vr_ur].buf->N_bytes < len) {