Staging: lirc: fix PTR_ERR() check

This is a typo.  It's supposed to be IS_ERR() here instead of PTR_ERR().
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/lirc/lirc_sasem.c

@@ -386,7 +386,7 @@ static ssize_t vfd_write(struct file *file, const char *buf,
 	}
 
 	data_buf = memdup_user(buf, n_bytes);
-	if (PTR_ERR(data_buf)) {
+	if (IS_ERR(data_buf)) {
 		retval = PTR_ERR(data_buf);
 		goto exit;
 	}