audit: make system check stricter with quotes.
audit: make system check stricter with quotes.

As mentioned in:
https://github.com/Homebrew/homebrew-core/pull/1396#discussion_r64774080

gordonmcshane/homebrew,hanxue/linuxbrew,Linuxbrew/brew,nandub/brew,muellermartin/dist,bfontaine/brew,pseudocody/brew,muellermartin/dist,konqui/brew,tonyg/homebrew,nandub/brew,bfontaine/brew,zmwangx/brew,rwhogg/brew,mahori/brew,vitorgalvao/brew,staticfloat/brew,MikeMcQuaid/brew,reelsense/brew,jmsundar/brew,ilovezfs/brew,JCount/brew,mgrimes/brew,nandub/brew,tonyg/homebrew,MikeMcQuaid/brew,alyssais/brew,rwhogg/brew,Homebrew/brew,aw1621107/brew,ilovezfs/brew,pseudocody/brew,mgrimes/brew,Linuxbrew/brew,konqui/brew,gregory-nisbet/brew,reelsense/brew,mgrimes/brew,sjackman/homebrew,gordonmcshane/homebrew,claui/brew,maxim-belkin/brew,aw1621107/brew,Linuxbrew/brew,DomT4/brew,reitermarkus/brew,gregory-nisbet/brew,DomT4/brew,jmsundar/brew,hanxue/linuxbrew,sjackman/homebrew,EricFromCanada/brew,Homebrew/brew,aw1621107/brew,rwhogg/brew,amar-laksh/brew_sudo,nandub/brew,toonetown/homebrew,alyssais/brew,vitorgalvao/brew,vitorgalvao/brew,claui/brew,gregory-nisbet/brew,zmwangx/brew,AnastasiaSulyagina/brew,Homebrew/brew,amar-laksh/brew_sudo,DomT4/brew,mahori/brew,gordonmcshane/homebrew,maxim-belkin/brew,EricFromCanada/brew,palxex/brew,konqui/brew,pseudocody/brew,AnastasiaSulyagina/brew,staticfloat/brew,reitermarkus/brew,JCount/brew,JCount/brew,EricFromCanada/brew,amar-laksh/brew_sudo,palxex/brew,palxex/brew,ilovezfs/brew,staticfloat/brew,mahori/brew,konqui/brew,muellermartin/dist,MikeMcQuaid/brew,toonetown/homebrew,toonetown/homebrew,claui/brew,jmsundar/brew,zmwangx/brew,Linuxbrew/brew,MikeMcQuaid/brew,tonyg/homebrew,sjackman/homebrew,reelsense/brew,DomT4/brew,bfontaine/brew,reitermarkus/brew,EricFromCanada/brew,reitermarkus/brew,claui/brew,alyssais/brew,Homebrew/brew,sjackman/homebrew,hanxue/linuxbrew,mahori/brew,JCount/brew,vitorgalvao/brew,AnastasiaSulyagina/brew,maxim-belkin/brew