usb: host: ehci-st: Remove set but not used variable 'ehci'

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

drivers/usb/host/ehci-st.c: In function st_ehci_platform_probe:
drivers/usb/host/ehci-st.c:155:19: warning: variable ehci set but not used [-Wunused-but-set-variable]

It is never used, so can be removed.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-st.c

@@ -152,7 +152,6 @@ static int st_ehci_platform_probe(struct platform_device *dev)
 	struct resource *res_mem;
 	struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
 	struct st_ehci_platform_priv *priv;
-	struct ehci_hcd *ehci;
 	int err, irq, clk = 0;
 
 	if (usb_disabled())
@@ -177,7 +176,6 @@ static int st_ehci_platform_probe(struct platform_device *dev)
 	platform_set_drvdata(dev, hcd);
 	dev->dev.platform_data = pdata;
 	priv = hcd_to_ehci_priv(hcd);
-	ehci = hcd_to_ehci(hcd);
 
 	priv->phy = devm_phy_get(&dev->dev, "usb");
 	if (IS_ERR(priv->phy)) {