[!] fix RETIRE_CID error when suffering severe loss

Author: Kulsk

src/transport/xqc_cid.c

@@ -250,7 +250,7 @@ xqc_int_t
 xqc_cid_switch_to_next_state(xqc_cid_set_t *cid_set, xqc_cid_inner_t *cid, xqc_cid_state_t next_state)
 {
     if (xqc_cid_in_cid_set(cid_set, &cid->cid) == NULL) {
-        return -XQC_ECONN_CID_NOT_FOUND;
+        return XQC_OK;
     }
 
     xqc_cid_state_t current_state = cid->state;
@@ -259,7 +259,7 @@ xqc_cid_switch_to_next_state(xqc_cid_set_t *cid_set, xqc_cid_inner_t *cid, xqc_c
         return XQC_OK;
 
     } else if (current_state > next_state) {
-        return -XQC_ECID_STATE;
+        return XQC_OK;
     }
 
     /* current_state < next_state */

src/transport/xqc_conn.c

@@ -4475,7 +4475,7 @@ xqc_conn_set_cid_retired_ts(xqc_connection_t *conn, xqc_cid_inner_t *inner_cid)
 
     ret = xqc_cid_switch_to_next_state(&conn->scid_set.cid_set, inner_cid, XQC_CID_RETIRED);
     if (ret != XQC_OK) {
-        xqc_log(conn->log, XQC_LOG_ERROR, "|set cid retired error|");
+        xqc_log(conn->log, XQC_LOG_ERROR, "|set cid retired error|ret:%d", ret);
         return ret;
     }