From the logs:
update-initramfs: Generating /boot/initrd.img-3.18.0-25-rpi2 Unsupported platform. run-parts: /etc/initramfs/post-update.d//flash-kernel exited with return code 1
From the logs:
update-initramfs: Generating /boot/initrd. img-3.18. 0-25-rpi2 post-update. d//flash- kernel exited with return code 1
Unsupported platform.
run-parts: /etc/initramfs/