The seastar api v4 changes the return type of when_all_succeed. This patch adds discard_result when that is best solution to handle the change. This doesn't do the actual update to v4 since there are still a few issues left to fix in seastar. A patch doing just the update will follow. Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com> Message-Id: <20200617233150.918110-1-espindola@scylladb.com>