KVM: vgic: declare probe function pointer as const

We extract the vgic probe function from the of_device_id data pointer,
which is const. Kill the sparse warning by ensuring that the local
function pointer is also marked as const.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index d1cfe67..efe6eee 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1557,8 +1557,8 @@
 int kvm_vgic_hyp_init(void)
 {
 	const struct of_device_id *matched_id;
-	int (*vgic_probe)(struct device_node *,const struct vgic_ops **,
-			  const struct vgic_params **);
+	const int (*vgic_probe)(struct device_node *,const struct vgic_ops **,
+				const struct vgic_params **);
 	struct device_node *vgic_node;
 	int ret;