KVM: ppc: improve trap emulation

set ESR[PTR] when emulating a guest trap. This allows Linux guests to
properly handle WARN_ON() (i.e. detect that it's a non-fatal trap).

Also remove debugging printk in trap emulation.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 814f1e6..4c30fa0 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -74,8 +74,8 @@
 	int advance = 1;
 
 	switch (get_op(inst)) {
-	case 3:                                                 /* trap */
-		printk("trap!\n");
+	case 3:                                             /* trap */
+		vcpu->arch.esr |= ESR_PTR;
 		kvmppc_core_queue_program(vcpu);
 		advance = 0;
 		break;