KVM: Remove ptr comparisons to 0

Fix sparse warnings "Using plain integer as NULL pointer"

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 3946025..7335435 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1449,7 +1449,8 @@
 
 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
 	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
-					   __alignof__(struct kvm_vcpu), 0, 0);
+					   __alignof__(struct kvm_vcpu),
+					   0, NULL);
 	if (!kvm_vcpu_cache) {
 		r = -ENOMEM;
 		goto out_free_4;