post-push patch for bug#47343.

Missing ha_rnd_end in copy_partitions, found due to a
DBUG_ASSERT in mysql-pe

sql/ha_partition.cc:
  Post-push patch for bug#47343
  
  Must call ha_rnd_end since ha_rnd_init has been called.

sql/ha_partition.cc

@@ -1705,6 +1705,7 @@ int ha_partition::copy_partitions(ulonglong * const copied,
   }
   DBUG_RETURN(FALSE);
 error:
+  m_reorged_file[reorg_part]->ha_rnd_end();
   DBUG_RETURN(result);
 }