KVM: Remove three magic numbers

There are several places where hardcoded numbers are used in place of
the easily-available constant, which is poor form.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 9a840e0..c18f0b2 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -241,7 +241,7 @@
 		printk(KERN_DEBUG "%s: NOP\n", __FUNCTION__);
 		return;
 	}
-	if (svm->next_rip - svm->vmcb->save.rip > 15) {
+	if (svm->next_rip - svm->vmcb->save.rip > MAX_INST_SIZE) {
 		printk(KERN_ERR "%s: ip 0x%llx next 0x%llx\n",
 		       __FUNCTION__,
 		       svm->vmcb->save.rip,