libcontainer/configs: add missing type for hooknames
libcontainer/configs: add missing type for hooknames

Commit ccdd75760c1f2d2be2dbb21522b67ceab28fd901 introduced the HookName type
for hooks, but only set this type on the Prestart const, but not for the
other hooks.

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

rhatdan/runc,dqminh/runc,opencontainers/runc,opencontainers/runc,rhatdan/runc,dqminh/runc,kolyshkin/runc,kolyshkin/runc,rhatdan/runc,opencontainers/runc,dqminh/runc,kolyshkin/runc,kolyshkin/runc,opencontainers/runc,dqminh/runc,rhatdan/runc