Don't treat link-time warnings as errors when linking with libbusybox
Don't treat link-time warnings as errors when linking with libbusybox

See http://review.cyanogenmod.org/#/c/46642/ for why this is necessary.

Change-Id: Ib97484755569fcafc062d3c39b2841581987ca72

kylinmoddev/android_bootable_recovery,DerTeufel/dualboot_recovery,DerTeufel/dualboot_recovery,InsomniaAOSP/platform_bootable_recovery,randomblame/bootable_recovery,76Demented/bootable_recovery-,76Demented/bootable_recovery-,InsomniaAOSP/platform_bootable_recovery,Plain-Andy/android_platform_bootable_recovery,DerTeufel/dualboot_recovery,kylinmoddev/android_bootable_recovery,InsomniaAOSP/platform_bootable_recovery,76Demented/bootable_recovery-,InsomniaAOSP/platform_bootable_recovery,kylinmoddev/android_bootable_recovery,Plain-Andy/android_platform_bootable_recovery,76Demented/bootable_recovery-,randomblame/bootable_recovery,kylinmoddev/android_bootable_recovery,randomblame/bootable_recovery,Plain-Andy/android_platform_bootable_recovery,randomblame/bootable_recovery,InsomniaAOSP/platform_bootable_recovery,DerTeufel/dualboot_recovery,Plain-Andy/android_platform_bootable_recovery,DerTeufel/dualboot_recovery,76Demented/bootable_recovery-,randomblame/bootable_recovery