wl12xx: use kstrtoul_from_user

simplify code by calling kstrtoul_from_user() (instead of
copy_from_user() + kstrtoul())
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/debugfs.c

@@ -265,18 +265,10 @@ static ssize_t gpio_power_write(struct file *file,
 			   size_t count, loff_t *ppos)
 {
 	struct wl1271 *wl = file->private_data;
-	char buf[10];
-	size_t len;
 	unsigned long value;
 	int ret;
 
-	len = min(count, sizeof(buf) - 1);
-	if (copy_from_user(buf, user_buf, len)) {
-		return -EFAULT;
-	}
-	buf[len] = '\0';
-
-	ret = kstrtoul(buf, 0, &value);
+	ret = kstrtoul_from_user(user_buf, count, 10, &value);
 	if (ret < 0) {
 		wl1271_warning("illegal value in gpio_power");
 		return -EINVAL;
@@ -427,17 +419,10 @@ static ssize_t dtim_interval_write(struct file *file,
 				   size_t count, loff_t *ppos)
 {
 	struct wl1271 *wl = file->private_data;
-	char buf[10];
-	size_t len;
 	unsigned long value;
 	int ret;
 
-	len = min(count, sizeof(buf) - 1);
-	if (copy_from_user(buf, user_buf, len))
-		return -EFAULT;
-	buf[len] = '\0';
-
-	ret = kstrtoul(buf, 0, &value);
+	ret = kstrtoul_from_user(user_buf, count, 10, &value);
 	if (ret < 0) {
 		wl1271_warning("illegal value for dtim_interval");
 		return -EINVAL;
@@ -492,17 +477,10 @@ static ssize_t beacon_interval_write(struct file *file,
 				     size_t count, loff_t *ppos)
 {
 	struct wl1271 *wl = file->private_data;
-	char buf[10];
-	size_t len;
 	unsigned long value;
 	int ret;
 
-	len = min(count, sizeof(buf) - 1);
-	if (copy_from_user(buf, user_buf, len))
-		return -EFAULT;
-	buf[len] = '\0';
-
-	ret = kstrtoul(buf, 0, &value);
+	ret = kstrtoul_from_user(user_buf, count, 10, &value);
 	if (ret < 0) {
 		wl1271_warning("illegal value for beacon_interval");
 		return -EINVAL;
@@ -542,17 +520,10 @@ static ssize_t rx_streaming_interval_write(struct file *file,
 			   size_t count, loff_t *ppos)
 {
 	struct wl1271 *wl = file->private_data;
-	char buf[10];
-	size_t len;
 	unsigned long value;
 	int ret;
 
-	len = min(count, sizeof(buf) - 1);
-	if (copy_from_user(buf, user_buf, len))
-		return -EFAULT;
-	buf[len] = '\0';
-
-	ret = kstrtoul(buf, 0, &value);
+	ret = kstrtoul_from_user(user_buf, count, 10, &value);
 	if (ret < 0) {
 		wl1271_warning("illegal value in rx_streaming_interval!");
 		return -EINVAL;
@@ -601,17 +572,10 @@ static ssize_t rx_streaming_always_write(struct file *file,
 			   size_t count, loff_t *ppos)
 {
 	struct wl1271 *wl = file->private_data;
-	char buf[10];
-	size_t len;
 	unsigned long value;
 	int ret;
 
-	len = min(count, sizeof(buf) - 1);
-	if (copy_from_user(buf, user_buf, len))
-		return -EFAULT;
-	buf[len] = '\0';
-
-	ret = kstrtoul(buf, 0, &value);
+	ret = kstrtoul_from_user(user_buf, count, 10, &value);
 	if (ret < 0) {
 		wl1271_warning("illegal value in rx_streaming_write!");
 		return -EINVAL;