usb: fix usbtest halt check on big endian systems

usbtest did not swap the received status information when checking for
a non-zero value and failed to discover halted endpoints on big endian
systems.

Cc: stable <stable@kernel.org>
Signed-off-by: Jan Andersson <jan@gaisler.com>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>