usb: typec: fusb302: Make fusb302_irq_work static

Fix sparse warning:

drivers/usb/typec/tcpm/fusb302.c:1454:6: warning:
 symbol 'fusb302_irq_work' was not declared. Should it be static?
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tcpm/fusb302.c

@@ -1451,7 +1451,7 @@ static irqreturn_t fusb302_irq_intn(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-void fusb302_irq_work(struct work_struct *work)
+static void fusb302_irq_work(struct work_struct *work)
 {
 	struct fusb302_chip *chip = container_of(work, struct fusb302_chip,
 						 irq_work);