Revert "staging: usbip: bugfix for stack corruption on 64-bit architectures"

This reverts commit 08224262adefb5e6460888b2490a96e1bc28aef5 as it's
just not right.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Cc: stable <stable@vger.kernel.org>
Cc: Bart Westgeest <bart@elbrys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>