tests: Always put a '\n' after each debug print

tests: Always put a '\n' after each debug print

There is an inconsistency with VIR_TEST_DEBUG() calls. One half
(roughly) of calls does have the newline character the other one
doesn't. Well, it doesn't have it because it assumed blindly that
new line will be printed, which is not the case.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>