[CPUFREQ] Longrun validate can fail.

From Dominik

Instead of trying to guess what the user intended, fail if the user
requests a setting which is not supported by the longrun driver.

arch/i386/kernel/cpu/cpufreq/longrun.c

@@ -123,7 +123,7 @@ static int longrun_verify_policy(struct cpufreq_policy *policy)
 		policy->cpuinfo.max_freq);
 
 	if (policy->policy == CPUFREQ_POLICY_GOVERNOR)
-		policy->policy = longrun_driver.policy[0].policy;
+		return -EINVAL;
 
 	return 0;
 }