Fix file descriptor leak in Formula#system
Fix file descriptor leak in Formula#system

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