LU-10030 idl: use proper ATTR/MDS_ATTR/MDS_OPEN flags

LU-10030 idl: use proper ATTR/MDS_ATTR/MDS_OPEN flags

Add proper MDS_ATTR_* and MDS_OPEN_* flags for different flags
namespaces.  The MDS_OPEN_OWNEROVERRIDE was being mapped into
the MDS_ATTR_* flags in some cases.  This did not conflict yet, but
add separate ATTR_OVERRIDE and MDS_ATTR_OVERRIDE flags for this use
so they don't conflict in the future.

Remove the MDS_OPEN_CROSS flag, since this was only used internally
as a hack to pass open flags to mdd_permission(), but was truncating
the u64 open flags to a 32-bit int in the process.  Do the convert
to MAY_* flags at the MDT layer instead of inside mdd_permission()
by moving the accmode() flag conversion into lustre_mds.h code.

The ATTR_OPEN flag has existed since kernel 2.6.27, so we can always
use that directly instead of the ATTR_FROM_OPEN flag we #defined.
The ATTR_RAW flag is no longer used at all and can be removed.

Rename various "flags" uses in the code to "open_flags" so that it
is more clear which flags values are being used.  This exposed a few
places in the code where we were using an int to pass these flags, but
some of the MDS_OPEN_* flags are using 64-bit values already.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I833a6e6102f947a9276cb6bf03826fd4a5ecab07
Reviewed-on: https://review.whamcloud.com/32107
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>