KVM: arm/arm64: vgic: Preserve the revious read from the pending table

The current pending table parsing code assumes that we keep the
previous read of the pending bits, but keep that variable in
the current block, making sure it is discarded on each loop.

We end-up using whatever is on the stack. Who knows, it might
just be the right thing...

Fixes: 28077125 ("KVM: arm64: vgic-v3: KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES")
Cc: stable@vger.kernel.org # 4.12
Reported-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

virt/kvm/arm/vgic/vgic-v3.c

@@ -327,13 +327,13 @@ int vgic_v3_save_pending_tables(struct kvm *kvm)
 	int last_byte_offset = -1;
 	struct vgic_irq *irq;
 	int ret;
+	u8 val;
 
 	list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
 		int byte_offset, bit_nr;
 		struct kvm_vcpu *vcpu;
 		gpa_t pendbase, ptr;
 		bool stored;
-		u8 val;
 
 		vcpu = irq->target_vcpu;
 		if (!vcpu)