Origin for each line in nextboot.init.mk from check-in 7a1e7f4a58:

7a1e7f4a58 2019-10-21        arcade: nextboot: mount
7a1e7f4a58 2019-10-21        arcade: .if exists(/boot/nextkernel)
7a1e7f4a58 2019-10-21        arcade: 	echo "MRC:$@> Removing nextboot setting."
7a1e7f4a58 2019-10-21        arcade: 	rm -f /boot/nextkernel
7a1e7f4a58 2019-10-21        arcade: .endif