usb: renesas_usbhs: fixup inconsistent return from usbhs_pkt_push()

usbhs_pkt_push() had inconsistent return under spin lock.
This patch fix it up.
Special thanks to Dan

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index 762b742..8da685e 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -62,14 +62,14 @@
 	struct device *dev = usbhs_priv_to_dev(priv);
 	unsigned long flags;
 
-	/********************  spin lock ********************/
-	usbhs_lock(priv, flags);
-
 	if (!done) {
 		dev_err(dev, "no done function\n");
 		return;
 	}
 
+	/********************  spin lock ********************/
+	usbhs_lock(priv, flags);
+
 	if (!pipe->handler) {
 		dev_err(dev, "no handler function\n");
 		pipe->handler = &usbhsf_null_handler;