KVM: selftests: Rip out old, param-based guest assert macros

Drop the param-based guest assert macros and enable the printf versions
for all selftests.  Note!  This change can affect tests even if they
don't use directly use guest asserts!  E.g. via library code, or due to
the compiler making different optimization decisions.

Link: https://lore.kernel.org/r/20230729003643.1053367-33-seanjc@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>