KVM: vmx: remove duplicate vmx_mpx_supported() prototype

Remove a prototype which was added by both 93c4adc7 and 36be0b9d.
Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -743,7 +743,6 @@ static u32 vmx_segment_access_rights(struct kvm_segment *var);
 static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu);
 static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
 static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
-static bool vmx_mpx_supported(void);
 
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);