debugfs: move to new strtobool

No functional changes requires that we eat errors from strtobool.
If people want to not do this, then it should be fixed at a later date.

V2: Simplification suggested by Rusty Russell removes the need for
additional variable ret.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

fs/debugfs/file.c

@@ -429,24 +429,15 @@ static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
 {
 	char buf[32];
 	int buf_size;
+	bool bv;
 	u32 *val = file->private_data;
 
 	buf_size = min(count, (sizeof(buf)-1));
 	if (copy_from_user(buf, user_buf, buf_size))
 		return -EFAULT;
 
-	switch (buf[0]) {
-	case 'y':
-	case 'Y':
-	case '1':
-		*val = 1;
-		break;
-	case 'n':
-	case 'N':
-	case '0':
-		*val = 0;
-		break;
-	}
+	if (strtobool(buf, &bv) == 0)
+		*val = bv;
 
 	return count;
 }