Uninitialized variables in Pool
Uninitialized variables in Pool

Summary:
This fixes the issue where the opensource build wasn't being able to
open more connections due to these 2 uninitialized variables.

refs facebook/hhvm#5143

Test Plan: Built OSS  with @fredemmott env and checked

Reviewers: fredemmott, chip

Reviewed By: chip

Subscribers: anca, lins, fredemmott

Differential Revision: https://phabricator.fb.com/D2061657

Tasks: 7034262

Signature: t1:2061657:1431372591:10a11a0e6095803d0170b7a0830deb4116c2e947

linearregression/squangle