libcontainer/nsenter: Don't import C in non-cgo file
libcontainer/nsenter: Don't import C in non-cgo file

Signed-off-by: Jonathan Rudenberg <3692bfa45759a67d83aedf0045f6cb635a966abf@titanous.com>

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