Update zcache, cleanache, frontswap
Revert "mm: implement WasActive page flag (for improving cleancache)"

This reverts commit ba81f47e30e92dca39fad66c2e9b81ea3a906abb.
staging: zcache: crypto API support
staging: zcache: replace xvmalloc with zsmalloc
staging: zcache: avoid AB-BA deadlock condition
staging: zcache: fix length type mismatch
staging: zcache: fix memory corruption bug