KVM: arm64: Drop useless struct s2_mmu in __kvm_at_s1e2()

__kvm_at_s1e2() contains the definition of an s2_mmu for the
current context, but doesn't make any use of it. Drop it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241023145345.1613824-5-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

Author: Marc Zyngier

arch/arm64/kvm/at.c

@@ -992,12 +992,9 @@ void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 	 * switching context behind everybody's back, disable interrupts...
 	 */
 	scoped_guard(write_lock_irqsave, &vcpu->kvm->mmu_lock) {
-		struct kvm_s2_mmu *mmu;
 		u64 val, hcr;
 		bool fail;
 
-		mmu = &vcpu->kvm->arch.mmu;
-
 		val = hcr = read_sysreg(hcr_el2);
 		val &= ~HCR_TGE;
 		val |= HCR_VM;