usb: fotg210-hcd: Don't shadow error codes in store()

kstrtox() along with regmap API can return different error codes based on
circumstances.

Don't shadow them when returning to the caller.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230120154437.22025-2-andriy.shevchenko@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/fotg210/fotg210-hcd.c

@@ -4702,8 +4702,10 @@ static ssize_t uframe_periodic_max_store(struct device *dev,
 	ssize_t ret;
 
 	fotg210 = hcd_to_fotg210(bus_to_hcd(dev_get_drvdata(dev)));
-	if (kstrtouint(buf, 0, &uframe_periodic_max) < 0)
-		return -EINVAL;
+
+	ret = kstrtouint(buf, 0, &uframe_periodic_max);
+	if (ret)
+		return ret;
 
 	if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
 		fotg210_info(fotg210, "rejecting invalid request for uframe_periodic_max=%u\n",