marlin: update kernel prebuilt

cb942e1ef856 usb: gadget: composite: Handle OS descriptor request properly

Linux version 3.18.70-gcb942e1ef856 (android-
    build@wprh8.hot.corp.google.com) (gcc version 4.9.x 20150123
    (prerelease) (GCC) ) #1 SMP PREEMPT Tue Oct 17 18:15:33 UTC 2017

Bug: 66985760
Change-Id: I86584a3c8cf478a975f096304ffb70949f37aa3c
Source-Branch: android-msm-marlin-3.18
Signed-off-by: Siqi Lin <siqilin@google.com>