usb: phy: mv-usb: Remove set but not used variable 'phy'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/usb/phy/phy-mv-usb.c: In function mv_otg_work:
drivers/usb/phy/phy-mv-usb.c:404:18: warning: variable phy set but not used [-Wunused-but-set-variable]

It's no used since commit e47d9254 ("usb: move
the OTG state from the USB PHY to the OTG structure")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/phy/phy-mv-usb.c

@@ -401,7 +401,6 @@ static void mv_otg_update_state(struct mv_otg *mvotg)
 static void mv_otg_work(struct work_struct *work)
 {
 	struct mv_otg *mvotg;
-	struct usb_phy *phy;
 	struct usb_otg *otg;
 	int old_state;
 
@@ -409,7 +408,6 @@ static void mv_otg_work(struct work_struct *work)
 
 run:
 	/* work queue is single thread, or we need spin_lock to protect */
-	phy = &mvotg->phy;
 	otg = mvotg->phy.otg;
 	old_state = otg->state;