cpufreq: interactive: Add error checking on sysfs interfaces

This adds better error checking on tunable parameters on sysfs
interfaces.  Also fixes return value from these functions, previously
on success they would return 0 which would cause a infinite loop.

Change-Id: Ic05038492166f8673d007202092471f98a2f0dfa
Signed-off-by: Allen Martin <amartin@nvidia.com>
diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 9100c3b..fe20e31 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -394,7 +394,14 @@
 static ssize_t store_go_maxspeed_load(struct kobject *kobj,
 			struct attribute *attr, const char *buf, size_t count)
 {
-	return strict_strtoul(buf, 0, &go_maxspeed_load);
+	int ret;
+	unsigned long val;
+
+	ret = strict_strtoul(buf, 0, &val);
+	if (ret < 0)
+		return ret;
+	go_maxspeed_load = val;
+	return count;
 }
 
 static struct global_attr go_maxspeed_load_attr = __ATTR(go_maxspeed_load, 0644,
@@ -409,7 +416,14 @@
 static ssize_t store_min_sample_time(struct kobject *kobj,
 			struct attribute *attr, const char *buf, size_t count)
 {
-	return strict_strtoul(buf, 0, &min_sample_time);
+	int ret;
+	unsigned long val;
+
+	ret = strict_strtoul(buf, 0, &val);
+	if (ret < 0)
+		return ret;
+	min_sample_time = val;
+	return count;
 }
 
 static struct global_attr min_sample_time_attr = __ATTR(min_sample_time, 0644,