writer thread returns free lists before re-opening output, and after

a ready output timeout

src/writer.c

@@ -172,6 +172,7 @@ wrt_write(tx_t *tx)
 
     AZ(pthread_mutex_lock(&reopen_lock));
     if (reopen && fo != stdout) {
+        wrt_return_freelist();
         if (fflush(fo) != 0)
             LOG_Log(LOG_ERR, "Cannot flush to %s, DATA DISCARDED: %s",
                     config.output_file, strerror(errno));
@@ -209,6 +210,7 @@ wrt_write(tx_t *tx)
         }
     }
     else if (errnum == 0) {
+        wrt_return_freelist();
         LOG_Log(LOG_ERR,
                 "Timeout waiting for ready output, DATA DISCARDED: %s",
                 VSB_data(os));