KVM: arm64: Fix double-free following kvm_pgtable_stage2_free_unlinked()

kvm_pgtable_stage2_free_unlinked() does the final put_page() on the
root page of the sub-tree before returning, so remove the additional
put_page() invocations in the callers.

Cc: Ricardo Koller <ricarkol@google.com>
Fixes: f6a27d6 ("KVM: arm64: Drop last page ref in kvm_pgtable_stage2_free_removed()")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240212193052.27765-1-will@kernel.org

Author: willdeacon

arch/arm64/kvm/hyp/pgtable.c

@@ -1419,7 +1419,6 @@ kvm_pte_t *kvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt,
 				 level + 1);
 	if (ret) {
 		kvm_pgtable_stage2_free_unlinked(mm_ops, pgtable, level);
-		mm_ops->put_page(pgtable);
 		return ERR_PTR(ret);
 	}
 
@@ -1502,7 +1501,6 @@ static int stage2_split_walker(const struct kvm_pgtable_visit_ctx *ctx,
 
 	if (!stage2_try_break_pte(ctx, mmu)) {
 		kvm_pgtable_stage2_free_unlinked(mm_ops, childp, level);
-		mm_ops->put_page(childp);
 		return -EAGAIN;
 	}