cpufreq: Return index from cpufreq_frequency_table_target()

This routine can't fail unless the frequency table is invalid and
doesn't contain any valid entries.

Make it return the index and WARN() in case it is used for an invalid
table.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/amd_freq_sensitivity.c

@@ -91,8 +91,8 @@ static unsigned int amd_powersave_bias_target(struct cpufreq_policy *policy,
 		else {
 			unsigned int index;
 
-			cpufreq_frequency_table_target(policy,
-				policy->cur - 1, CPUFREQ_RELATION_H, &index);
+			index = cpufreq_frequency_table_target(policy,
+				policy->cur - 1, CPUFREQ_RELATION_H);
 			freq_next = policy->freq_table[index].frequency;
 		}