brew.sh: streamline setting HOMEBREW_{OSX,LINUX}
brew.sh: streamline setting HOMEBREW_{OSX,LINUX}

For uses like this one, `case` is much more compact and easier to read.

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