KVM: SVM: tweak warning about enabled AVIC on nested entry

It is possible that AVIC was requested to be disabled but
not yet disabled, e.g if the nested entry is done right
after svm_vcpu_after_set_cpuid.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210713142023.106183-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>