x86/kvm/vmx: remove unused variable in segment_base()

The pointer 'struct desc_struct *d' is unused since commit 8c2e41f7
("x86/kvm/vmx: Simplify segment_base()") so let's remove it.
Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

arch/x86/kvm/vmx.c

@@ -2053,7 +2053,6 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
 static unsigned long segment_base(u16 selector)
 {
 	struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
-	struct desc_struct *d;
 	struct desc_struct *table;
 	unsigned long v;