Minor tweak to glsa-check to show '0' when all tests are compliant

As the subject says....

Currently the test expects all responses to include text that indicates GLSAs exist.  This just adds text exclusion when NO GLSAs are present.

Tested on both vulnerable and non-vulnerable gentoo systems.  Reports when GLSAs are applicable, as expected, on vulnerable systems.  Also report that no GLSas are applicable for systems that are clean.