[hack] Daemon.fork should correctly close channels
[hack] Daemon.fork should correctly close channels

Summary:
Due to rFBS18d86555d0eb2efa7745bdf270c86aeda637c686, we have separate
FD's for each direction even in socket mode. So we need to close both
of them after fork.

Reviewed By: dabek

Differential Revision: D7623099

fbshipit-source-id: 064684a316a21ea77d563e35979d7267e0bf79c4

gabelevi/flow,AgentME/flow,jamesgpearce/flow,facebook/flow,AgentME/flow,samwgoldman/flow,claudiopro/flow,mroch/flow,mroch/flow,facebook/flow,mroch/flow,facebook/flow,AgentME/flow,JonathanUsername/flow,gabelevi/flow,claudiopro/flow,mroch/flow,JonathanUsername/flow,mroch/flow,jamesgpearce/flow,popham/flow,samwgoldman/flow,claudiopro/flow,popham/flow,mroch/flow,nmote/flow,popham/flow,AgentME/flow,nmote/flow,JonathanUsername/flow,samwgoldman/flow,gabelevi/flow,JonathanUsername/flow,facebook/flow,JonathanUsername/flow,nmote/flow,samwgoldman/flow,nmote/flow,samwgoldman/flow,gabelevi/flow,JonathanUsername/flow,nmote/flow,facebook/flow,gabelevi/flow,mroch/flow,jamesgpearce/flow,gabelevi/flow,facebook/flow,jamesgpearce/flow,AgentME/flow,popham/flow,samwgoldman/flow,gabelevi/flow,nmote/flow,popham/flow,claudiopro/flow,nmote/flow,popham/flow,facebook/flow,jamesgpearce/flow,JonathanUsername/flow,jamesgpearce/flow,jamesgpearce/flow,samwgoldman/flow,popham/flow,claudiopro/flow