Revert "memcg: fix GPF when cgroup removal races with last exit"

This reverts commit 407c965604bcf347610d693b7c2c0f7b64488a33.

Conflicts:
	mm/memcontrol.c
Revert "mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages"

This reverts commit 294a6538de80d7fa949e4ab289a3b876645bf52b.

Conflicts:
	include/linux/fs.h
	mm/page_io.c
	mm/swapfile.c
mm/page-writeback : fix warnings
SmittyV-rv3