KVM: vmx: delete meaningless nested_vmx_prepare_msr_bitmap() declaration

The function nested_vmx_prepare_msr_bitmap() declaration is below its
implementation. So this is meaningless and should be removed.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/nested.c

@@ -3048,9 +3048,6 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
-						 struct vmcs12 *vmcs12);
-
 static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
 {
 	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);