main/lbd: broken test on s390x
On s390x, when building kbd 2.2.0, one test fails:
PASS: dumpkeys-mktable
PASS: alt-is-meta
FAIL: dumpkeys-bkeymap
PASS: dumpkeys-fulltable
============================================================================
Testsuite summary for kbd 2.2.0
============================================================================
# TOTAL: 34
# PASS: 33
# SKIP: 0
# XFAIL: 0
# FAIL: 1
# XPASS: 0
# ERROR: 0