btrfs-progs: drop dependency on e2fsprogs by not building btrfs-convert

btrfs-progs: drop dependency on e2fsprogs by not building btrfs-convert

The btrfs-convert tool is used to convert an existing ext2 or reiserfs
filesystem into a btrfs filesystem. On the host, this is not really
useful, so let's disable building this tool, which allows to drop the
host-e2fsprogs dependency.

The host-util-linux dependency becomes necessary: it was previously
brought as a second-order dependency of host-e2fsprogs, but since we
no longer depend on host-e2fsprogs, we now need to explicitly depend
on host-util-linux.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>