KVM: x86: Get vcpu->arch.apic_base directly and drop kvm_get_apic_base()

KVM: x86: Get vcpu->arch.apic_base directly and drop kvm_get_apic_base()

[ Upstream commit d91060e342a66b52d9bd64f0b123b9c306293b76 ]

Access KVM's emulated APIC base MSR value directly instead of bouncing
through a helper, as there is no reason to add a layer of indirection, and
there are other MSRs with a "set" but no "get", e.g. EFER.

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20241009181742.1128779-4-seanjc@google.com
Link: https://lore.kernel.org/r/20241101183555.1794700-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Stable-dep-of: 04bc93cf49d1 ("KVM: nVMX: Defer SVI update to vmcs01 on EOI when L2 is active w/o VID")
Signed-off-by: Sasha Levin <sashal@kernel.org>