KVM: x86: Use "is Intel compatible" helper to emulate SYSCALL in !64-bit

Use guest_cpuid_is_intel_compatible() to determine whether SYSCALL in
32-bit Protected Mode (including Compatibility Mode) should #UD or succeed.
The existing code already does the exact equivalent of
guest_cpuid_is_intel_compatible(), just in a rather roundabout way.

No functional change intended.

Link: https://lore.kernel.org/r/20240405235603.1173076-7-seanjc@google.com


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