Construct TestObject in AtomicLinkedListTest via a const reference
Construct TestObject in AtomicLinkedListTest via a const reference

Summary:
MSVC doesn't currently guarantee left-to-right argument evaluation order for values constructed via braced initializers, and produces a warning if you try to pass an argument with a non-trivial copy constructor by-value in a constructor used by the braced initializer.
This prevents the warning by simply accepting a const reference instead.

Reviewed By: yfeldblum

Differential Revision: D3705073

fbshipit-source-id: 917ec1bb776d6ec4bfefe50907d4c5ac2f2379b1

Orvid/folly,Orvid/folly,charsyam/folly,facebook/folly,facebook/folly,floxard/folly,charsyam/folly,facebook/folly,floxard/folly,charsyam/folly,floxard/folly,floxard/folly,rklabs/folly,rklabs/folly,rklabs/folly,facebook/folly,Orvid/folly,rklabs/folly,rklabs/folly,Orvid/folly,Orvid/folly,facebook/folly,floxard/folly,charsyam/folly