Revert "android/lowmemorykiller: Ignore tasks with freed mm"

This reverts commit 217cfe5d6eedd6395c056b85f7c2d320b562ed0f.
Revert "ARM: Add smp barriers to mutex fastpath routines"

This reverts commit 17e39a34aaa0b07dfeb6fb9d9b9a04f75ec19d1e.