KVM: selftests: Convert x86's TSC MSRs test to use printf guest asserts

Convert x86's TSC MSRs test, and it's liberal use of GUEST_ASSERT_EQ(), to
use printf-based guest assert reporting.

Link: https://lore.kernel.org/r/20230729003643.1053367-29-seanjc@google.com


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