[backend][serialization] Fix flushing of temp file in serialization write
[backend][serialization] Fix flushing of temp file in serialization write

Reviewed By: jberdine

Differential Revision: D4697588

fbshipit-source-id: 1a56e7a

jvillard/infer,jvillard/infer,facebook/infer,ropas/infer,ropas/infer,ropas/infer,ryoon/infer,ryoon/infer,ryoon/infer,facebook/infer,ryoon/infer,ropas/infer,facebook/infer,blzq/infer,ropas/infer,jvillard/infer,jsachs/infer,jvillard/infer,facebook/infer,facebook/infer,jsachs/infer,ropas/infer,blzq/infer,blzq/infer,jsachs/infer,jsachs/infer,blzq/infer,jvillard/infer,jsachs/infer,ryoon/infer,blzq/infer,ryoon/infer,facebook/infer,blzq/infer,jvillard/infer,facebook/infer,jvillard/infer,jsachs/infer