KVM: selftests: Convert x86's CPUID test to printf style GUEST_ASSERT

Convert x86's CPUID test to use printf-based GUEST_ASSERT_EQ() so that
the test prints out debug information.  Note, the test previously used
REPORT_GUEST_ASSERT_2(), but that was pointless because none of the
guest-side code passed any parameters to the assert.

Link: https://lore.kernel.org/r/20230729003643.1053367-21-seanjc@google.com


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