libcontainer: remove unneeded sprintf and intermediate variable
libcontainer: remove unneeded sprintf and intermediate variable

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

dqminh/runc,estesp/runc,kolyshkin/runc,dqminh/runc,estesp/runc,rhatdan/runc,opencontainers/runc,estesp/runc,kolyshkin/runc,rhatdan/runc,opencontainers/runc,xiaochenshen/runc,kolyshkin/runc,rhatdan/runc,rhatdan/runc,xiaochenshen/runc,dqminh/runc,xiaochenshen/runc,opencontainers/runc,kolyshkin/runc,opencontainers/runc,dqminh/runc