Check written socket data of all subtests.
socket data, kern_priority:
<8>Feb 13 23:31:30 prio: message

socket data, kern_priority_numeric:
<8>Feb 13 23:31:30 prio: message

socket data, invalid_prio:

socket data, rfc5424_exceed_size:
<13>1 2009-02-13T23:31:30.123456+00:00 test-hostname rfc5424_exceed_size - - [timeQuality tzKnown="1" isSynced="0"] abc

socket data, id_with_space:

