KVM: x86: Simplify kvm_apic_hw_enabled

kvm_apic_hw_enabled() only needs to return bool, there is no place
to use the return value of MSR_IA32_APICBASE_ENABLE.

Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Message-Id: <CAPm50aJ=BLXNWT11+j36Dd6d7nz2JmOBk4u7o_NPQ0N61ODu1g@mail.gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>