STY: Style fixes to quicksort.cpp
STY: Style fixes to quicksort.cpp

jakirkham/numpy,jakirkham/numpy,charris/numpy,anntzer/numpy,mattip/numpy,pdebuyl/numpy,mhvk/numpy,rgommers/numpy,pdebuyl/numpy,anntzer/numpy,endolith/numpy,charris/numpy,anntzer/numpy,seberg/numpy,numpy/numpy,numpy/numpy,mattip/numpy,anntzer/numpy,rgommers/numpy,rgommers/numpy,jakirkham/numpy,pdebuyl/numpy,mhvk/numpy,mattip/numpy,mhvk/numpy,rgommers/numpy,charris/numpy,endolith/numpy,mattip/numpy,endolith/numpy,mhvk/numpy,jakirkham/numpy,jakirkham/numpy,numpy/numpy,mhvk/numpy,seberg/numpy,charris/numpy,pdebuyl/numpy,endolith/numpy,numpy/numpy,seberg/numpy,seberg/numpy