[Buildroot] JFFS2 / MTD suggestions

[Thomas Petazzoni]

Hi,

When selecting jffs2 as the output filesystem, mtd-utils gets compiled
both on the host and on the target. I think that generating a jffs2
filesystem image should *not* trigger the compilation/installation of
mtd-utils inside the target since this is not necessary.

Moreover, the compilation of host mtd-utils fails with "lzo/lzo1.h not
found" if the liblzo-dev package is not installed on the host. We
should probably add a test checking this and telling the user to
install liblzo-dev, because the current state is quite confusing.

Sincerly,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com