cleans up lsbmajdistrelease

The old spec file incorrect attributed lsb_release instead of lsbdistrelease and used version 10.10, which is ambiguous as the test did not show if the got the first 10 or the incorrect second 10.

Tests now reflect that lsbmajdistrelease is derived from lsbdistrelease, use a sensible version string, and check for the case of an unsupported kernel.