This reverts commit de80424f70 which needs
more work and testing as it broke at least jffs2 overlays at least on
ath79 platform, marking them as read-only, thus unusable:
jffs2_build_filesystem(): erasing all blocks after the end marker...
jffs2: Erase at 0x009e0000 failed immediately: -EROFS. Is the sector locked?
Ref: http://lists.infradead.org/pipermail/openwrt-devel/2020-January/021344.html
Reported-by: Steve Brown <sbrown@ewol.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz>