Revert "trace: memkill: trace LMK and OOM kills"

This reverts commit 585a47e7d0ee5b735227e01c6c2c61aa34892cfe.
Revert "trace: allow memkill tracing to be selectively enabled"

This reverts commit 73e2b76c5649266df43af32d0a7a7d203344dd7f.
HTC: remove even more meminfo debugging