Commit 31d2dda3 ("build-system: remove per-test GCOV reporting", 2018-06-20)
removed users of the variables, since those uses can be replaced by a simple
overall report produced by gcovr.  However, the variables were never removed.
Do it now.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
[thuth: Fixed up contextual conflicts with the patch from Eric]
Signed-off-by: NThomas Huth <thuth@redhat.com>