KVM: x86: X86_FEATURE_NRIPS is not scattered anymore

bit(X86_FEATURE_NRIPS) is 3 since 2ccd71f1 ("x86/cpufeature: Move
some of the scattered feature bits to x86_capability"), so we can
simplify the code.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>