Lots of packages fail in buildbot (cryptodev-linux, hostapd, openssl, ...)

[Hannu Nyman]

Notified by forum discussion, I noticed that lots of packages seem to fail to 
build in buildbot.

Faillogs e.g. in

* 
https://downloads.openwrt.org/snapshots/faillogs/arm_cortex-a15_neon-vfpv4/packages/
* https://downloads.openwrt.org/snapshots/faillogs/mipsel_24kc/packages/
* https://downloads.openwrt.org/snapshots/faillogs/mipsel_24kc/base/
* 
https://downloads.openwrt.org/snapshots/faillogs/arm_cortex-a9_vfpv3-d16/packages/
* https://downloads.openwrt.org/snapshots/faillogs/x86_64/base/

The problem seems not to be tied to a specific architecture, as there are 
major failures in x86, arm and mips.

Due to the large number of failures it is hard to find what is the ultimate 
culprit in the dependency chain, but cryptodev-linux failure leads into 
openssl and hostapd failing, cascading to lots of packages.

Nothing obvious jumps from the commits logs, but there have been several 
build system targeting patches from @nbd in the last 1-2 days.