fix probable typo

I think this is another typo.

There's also a more subtle problem: jordan-blobs.mk is read before BoardConfig.mk, so the test for TARGET_USE_KERNEL_BACKPORTS will never work. Maybe we should make Android.mk include jordan-blobs.mk?

(BTW, I'm still having to disable the new logwrapper/bootmenu setup, though that might be because of local changes).