Revert "KVM: x86 emulator: Report unhandled instructions"

This reverts commit ea67fbbcf346a15b1e8e18cff7c64c248972b961.  Unhandled
instructions can and do occur in normal runs.  This needs to be made optional
so as not to spam the logs.
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/emulate.c

@@ -2194,7 +2194,6 @@ writeback:
 
 done:
 	if (rc == X86EMUL_UNHANDLEABLE) {
-		kvm_report_emulation_failure(ctxt->vcpu, "unhandled instruction");
 		c->eip = saved_eip;
 		return -1;
 	}
@@ -2468,7 +2467,7 @@ twobyte_insn:
 	goto writeback;
 
 cannot_emulate:
-	kvm_report_emulation_failure(ctxt->vcpu, "unhandled instruction");
+	DPRINTF("Cannot emulate %02x\n", c->b);
 	c->eip = saved_eip;
 	return -1;
 }