usb: cdns3: fix missing assignment of ret before error check on ret

Currently the check on a non-zero return code in ret is false because
ret has been initialized to zero.  I believe that ret should be assigned
to the return from the call to readl_poll_timeout_atomic before the
check on ret.  Since ret is being re-assinged the original initialization
of ret to zero can be removed.

Addresses-Coverity: ("'Constant' variable guards dead code")
Fixes: 7733f6c32e ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190902145035.18200-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/cdns3/gadget.c

@@ -2152,7 +2152,7 @@ int __cdns3_gadget_ep_clear_halt(struct cdns3_endpoint *priv_ep)
 {
 	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
 	struct usb_request *request;
-	int ret = 0;
+	int ret;
 	int val;
 
 	trace_cdns3_halt(priv_ep, 0, 0);
@@ -2160,8 +2160,8 @@ int __cdns3_gadget_ep_clear_halt(struct cdns3_endpoint *priv_ep)
 	writel(EP_CMD_CSTALL | EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
 
 	/* wait for EPRST cleared */
-	readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
-				  !(val & EP_CMD_EPRST), 1, 100);
+	ret = readl_poll_timeout_atomic(&priv_dev->regs->ep_cmd, val,
+					!(val & EP_CMD_EPRST), 1, 100);
 	if (ret)
 		return -EINVAL;