Merge branch 'ubifs_from_4.2.0-rc5' into 'msm-3.18'

UBIFS over UBI is the default filesystem used in QCOM chipsets
that use NAND storage.

There were a few changes upstream to UBIFS that fixed some bugs
and added some more asserts. There were also changes to the
debug messages that would allow for much easier debug of filesystem
issues.

Backport and bring in all the changes to ensure stability and
better performance for the NAND based devices.

* The patches included are:

  ubifs: fix to check error code of register_shrinker
  UBIFS: fix output format of INUM_WATERMARK
  UBIFS: extend debug/message capabilities
  UBIFS: simplify returns
  UBIFS: Fix trivial typos in comments
  UBIFS: do not write master node if need recovery
  UBIFS: fix incorrect unlocking handling
  UBIFS: return -EINVAL if log head is empty
  UBIFS: add a couple of extra asserts
  UBIFS: add ubifs_err() to print error reason
  UBIFS: Add security.* XATTR support for the UBIFS
  UBIFS: Add xattr support for symlinks
  UBIFS: fix a couple bugs in UBIFS xattr length calculation
  UBIFS: fix budget leak in error path

Change-Id: I5e76bb39daa85b0d798b030b15d07069144ba82e
Signed-off-by: Nikhilesh Reddy <reddyn@codeaurora.org>