When we use an external kernel tree which may not have been fully
cleaned, there may be user_headers left which do not match the target
architecture, leading to build failures for packages that do an explicit
inclusion of user_headers (such as iproute2 or iptables). Make sure we
delete them while preparing the directory.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
09760cbb3b
