usb: isp1760: Fix meaningless check in isp1763_run()

Remove attribution to retval before check, which make it completely
meaningless, and does't check what it was supposed: the return
value of the timed function to set up configuration flag.

Fixes: 60d789f3 ("usb: isp1760: add support for isp1763")
Tested-by: NRui Miguel Silva <rui.silva@linaro.org>
Reviewed-by: NRui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: NTong Tiangen <tongtiangen@huawei.com>
Link: https://lore.kernel.org/r/20210611014055.68551-1-tongtiangen@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/isp1760/isp1760-hcd.c

@@ -1648,7 +1648,6 @@ static int isp1763_run(struct usb_hcd *hcd)
 	down_write(&ehci_cf_port_reset_rwsem);
 	retval = isp1760_hcd_set_and_wait(hcd, FLAG_CF, 250 * 1000);
 	up_write(&ehci_cf_port_reset_rwsem);
-	retval = 0;
 	if (retval)
 		return retval;