tests: Run virt-aa-helper-test only when the helper was compiled

'virt-aa-helper' is compiled when both WITH_LIBVIRTD and
WITH_SECDRIVER_APPARMOR are defined. The test was run only when
WITH_SECDRIVER_APPARMOR was defined thus causing a build failure when
building without the daemon.

tests/Makefile.am

@@ -423,10 +423,11 @@ endif ! WITH_LIBVIRTD
 test_programs += objecteventtest
 
 if WITH_SECDRIVER_APPARMOR
+if WITH_LIBVIRTD
 test_scripts += virt-aa-helper-test
-else ! WITH_SECDRIVER_APPARMOR
+endif WITH_LIBVIRTD
+endif WITH_SECDRIVER_APPARMOR
 EXTRA_DIST += virt-aa-helper-test
-endif ! WITH_SECDRIVER_APPARMOR
 
 EXTRA_DIST += $(test_scripts)