fix missing -lrt for Centos6, issue: #7552 (#7597)
fix missing -lrt for Centos6, issue: #7552 (#7597)

* fix missing -lrt for Centos6, issue: #7552

* fix missing -lrt for Centos6, issue: #7552

* fix using make() as opposed to patching

* remove patch, as the fix is provided withing package.py instead

* make flake8 happy

tmerrick1/spack,iulian787/spack,matthiasdiener/spack,matthiasdiener/spack,mfherbst/spack,krafczyk/spack,iulian787/spack,matthiasdiener/spack,iulian787/spack,mfherbst/spack,krafczyk/spack,krafczyk/spack,mfherbst/spack,tmerrick1/spack,tmerrick1/spack,LLNL/spack,iulian787/spack,mfherbst/spack,tmerrick1/spack,mfherbst/spack,matthiasdiener/spack,LLNL/spack,krafczyk/spack,krafczyk/spack,LLNL/spack,LLNL/spack,iulian787/spack,LLNL/spack,tmerrick1/spack,matthiasdiener/spack