Fixing coccicheck warning which recommends to use memdup_user instead
to reimplement its code, using memdup_user simplifies the code

./drivers/usb/core/devio.c:1398:11-18: WARNING opportunity for memdup_user
Signed-off-by: NRahul Pathak <rpathak@visteon.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>