Temporarily Revert [platform process list] add a flag for showing the processes of all users

as it breaks the bots.

This reverts r374609 (git commit 696d3cf8ad6f3a0b3019c87526d561bb77ad538e)

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@374616 91177308-0d34-0410-b5e6-96231b3b80d8