LU-10030 clio: don't use spare bits in iattr.ia_valid

LU-10030 clio: don't use spare bits in iattr.ia_valid

Using spare bits in iattr.ia_valid is not safe as the
bits might get used for some other purpose without
us noticing.

Lustre currently used 4 spare bit, but they are all
defined in different places so this isn't immediately
obvious.

This patch brings all those bit definitions together
and defined a new op_data field (op_xvalid) to hold
the extra validity bits.

It also replaces sa_valid in struct cl_setattr_io
with sa_avalid and sa_xvalid.  Changing the name is
helpful as sa_valid already has another use within
lustre.

Modified version of:
Linux-commit: 599b9fb8d424c7907325037b5a862221b1232526

Change-Id: I475a16d557143c0741472e5873c83d71968d7cb8
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/32825
Reviewed-by: Wang Shilong <wshilong@ddn.com>
Tested-by: Jenkins
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>