Revert "SELinux: Reduce overhead of mls_level_isvalid() function call"

This reverts commit 8dcbb655f1629d3cd2dae696f279357ff0deeabc.
Revert "binfmt_elf.c: use get_random_int() to fix entropy depleting"

This reverts commit e0dea3ed6918ae9e48c8f71955990b966a980f45.
Revert "mm: vmscan: when kswapd is awoken due to reclaim by a running task"

This reverts commit 02e44b2f317abb08cdc4283b97fda0d996173e61.