Staging: ft1000: fix world writable debugfs file

You should not be able to write to a debugfs file from any user.

Cc: Marek Belisko <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c

···
 		goto debug_dir_fail;
 	}
 
-	file = debugfs_create_file("device", S_IRUGO | S_IWUGO, dir,
+	file = debugfs_create_file("device", S_IRUGO | S_IWUSR, dir,
 					NULL, &ft1000fops);
 	if (IS_ERR(file)) {
 		result = PTR_ERR(file);