Revert "fs/dyn_sync_cntrl: dynamic sync control"

This reverts commit bdaae0a784c288baaa657b4dbd7f2be9eee403de.

	modified:   fs/Kconfig
	modified:   fs/Makefile
	deleted:    fs/dyn_sync_cntrl.c
	modified:   fs/sync.c
	modified:   include/linux/fs.h