super/cc: Remove redundant RPATH for Linuxbrew
super/cc: Remove redundant RPATH for Linuxbrew

Using -rpath=/a -rpath=/a:/b results in /a:/a:/b whereas
using -rpath=/a -rpath=/a -rpath=/b results in /a:/b

maxim-belkin/brew,rwhogg/brew,hanxue/linuxbrew,rwhogg/brew,Linuxbrew/brew,hanxue/linuxbrew,Linuxbrew/brew,maxim-belkin/brew,rwhogg/brew,maxim-belkin/brew,Linuxbrew/brew,hanxue/linuxbrew,Linuxbrew/brew