usb: misc: usbtest: remove redundant check on retval < 0

The check for retval being less than zero is always true since
retval equal to -EPIPE at that point.  Replace the existing
conditional with just return retval.

Detected with CoverityScan, CID#114349 ("Logically dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/usbtest.c

@@ -992,7 +992,7 @@ static int ch9_postconfig(struct usbtest_dev *dev)
 				dev_err(&iface->dev,
 						"hs dev qualifier --> %d\n",
 						retval);
-				return (retval < 0) ? retval : -EDOM;
+				return retval;
 			}
 			/* usb2.0 but not high-speed capable; fine */
 		} else if (retval != sizeof(struct usb_qualifier_descriptor)) {