libcontainer: devices: fix mips builds
libcontainer: devices: fix mips builds

It turns out that MIPS uses uint32 in the device number returned by
stat(2), so explicitly wrap everything to make the compiler happy. I
really wish that Go had C-like numeric type promotion.

Signed-off-by: Aleksa Sarai <a8eb12d32d6ec07cdf737175ec7d4a0f1b4e1ee7@suse.de>

opencontainers/runc,kolyshkin/runc,dqminh/runc,laijs/runc,crosbymichael/runc,mikebrow/runc,rhatdan/runc,xiaochenshen/runc,estesp/runc,adrianreber/runc,mheon/runc,cyphar/runc,justincormack/runc,opencontainers/runc,rhatdan/runc,mikebrow/runc,justincormack/runc,cyphar/runc,adrianreber/runc,mikebrow/runc,kolyshkin/runc,rhatdan/runc,crosbymichael/runc,mYmNeo/runc,opencontainers/runc,kolyshkin/runc,adrianreber/runc,mYmNeo/runc,cyphar/runc,justincormack/runc,dqminh/runc,xiaochenshen/runc,opencontainers/runc,xiaochenshen/runc,crosbymichael/runc,dqminh/runc,laijs/runc,kolyshkin/runc,mheon/runc,mheon/runc,laijs/runc,rhatdan/runc,dqminh/runc,estesp/runc,mYmNeo/runc,estesp/runc