Use apk --print-arch to discover architecture
Use apk --print-arch to discover architecture

When dealing with apk, `uname -m` doesn't always match the architecture
name that apk uses. Instead `apk --print-arch` is used.

Signed-off-by: Alan Raison <e61c72481b39f94f0a68fc59055efef4b1378f3d@users.noreply.github.com>

YuPengZTE/linuxkit,djs55/linuxkit,rn/linuxkit,rn/linuxkit,yankcrime/linuxkit,djs55/linuxkit,furious-luke/linuxkit,konstruktoid/linuxkit,YuPengZTE/linuxkit,linuxkit/linuxkit,yankcrime/linuxkit,YuPengZTE/linuxkit,deitch/linuxkit,deitch/linuxkit,YuPengZTE/linuxkit,linuxkit/linuxkit,konstruktoid/linuxkit,yankcrime/linuxkit,justincormack/linuxkit,justincormack/linuxkit,furious-luke/linuxkit,JohnnyLeone/linuxkit,linuxkit/linuxkit,justincormack/linuxkit,JohnnyLeone/linuxkit,deitch/linuxkit,furious-luke/linuxkit,yankcrime/linuxkit,konstruktoid/linuxkit,justincormack/linuxkit,linuxkit/linuxkit,JohnnyLeone/linuxkit,furious-luke/linuxkit,linuxkit/linuxkit,djs55/linuxkit,justincormack/linuxkit,yankcrime/linuxkit,deitch/linuxkit,yankcrime/linuxkit,konstruktoid/linuxkit,furious-luke/linuxkit,JohnnyLeone/linuxkit,JohnnyLeone/linuxkit,justincormack/linuxkit,YuPengZTE/linuxkit,YuPengZTE/linuxkit,konstruktoid/linuxkit,rn/linuxkit,rn/linuxkit,djs55/linuxkit,deitch/linuxkit,konstruktoid/linuxkit,djs55/linuxkit,rn/linuxkit