Autobuilder.pm: do not be confused by new automake unit test

# TOTAL: 66
# PASS: 66
# SKIP: 0
# XFAIL: 0
# FAIL: 0
# XPASS: 0
ERROR: # 0

means there were 0 error and should not be painted red.

Signed-off-by: Sage Weil <sage@inktank.com>