[SCSI] sg: convert to kstrtoul_from_user()

Instead of open coding this function use kstrtoul_from_user() directly.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/sg.c

@@ -2368,16 +2368,15 @@ static ssize_t
 sg_proc_write_adio(struct file *filp, const char __user *buffer,
 		   size_t count, loff_t *off)
 {
-	int num;
-	char buff[11];
+	int err;
+	unsigned long num;
 
 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 		return -EACCES;
-	num = (count < 10) ? count : 10;
-	if (copy_from_user(buff, buffer, num))
-		return -EFAULT;
-	buff[num] = '\0';
-	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
+	err = kstrtoul_from_user(buffer, count, 0, &num);
+	if (err)
+		return err;
+	sg_allow_dio = num ? 1 : 0;
 	return count;
 }
 
@@ -2390,17 +2389,15 @@ static ssize_t
 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
 		     size_t count, loff_t *off)
 {
-	int num;
+	int err;
 	unsigned long k = ULONG_MAX;
-	char buff[11];
 
 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 		return -EACCES;
-	num = (count < 10) ? count : 10;
-	if (copy_from_user(buff, buffer, num))
-		return -EFAULT;
-	buff[num] = '\0';
-	k = simple_strtoul(buff, NULL, 10);
+
+	err = kstrtoul_from_user(buffer, count, 0, &k);
+	if (err)
+		return err;
 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
 		sg_big_buff = k;
 		return count;