Fix the check for naming the thread on Linux
Fix the check for naming the thread on Linux

Kitware/sprokit,mathstuf/sprokit,mathstuf/sprokit,Kitware/sprokit,linus-sherrill/sprokit,Kitware/sprokit,Kitware/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,linus-sherrill/sprokit,mathstuf/sprokit,linus-sherrill/sprokit