LU-12275 sec: force file name encryption policy to null

Force file/directory name encryption policy to null on newly created
inodes. This is required because first implementation step of client
side encryption only supports content encryption, and not names.
This imposes to force usage of embedded llcrypt lib to the detriment
of in-kernel fscrypt lib, even if the kernel provides it.

This patch will have to be reverted when name encryption is
implemented.

Test-Parameters: testlist=sanity-sec envdefinitions=ONLY="36 37 38 39 40 41 42 43 44 45 46 47 48" clientdistro=el8.1 fstype=ldiskfs mdscount=2 mdtcount=4
Test-Parameters: testlist=sanity-sec envdefinitions=ONLY="36 37 38 39 40 41 42 43 44 45 46 47 48" clientdistro=el8.1 fstype=zfs mdscount=2 mdtcount=4
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: Ia697a29006507278c218088d7c3a5e5ade620a15
Reviewed-on: https://review.whamcloud.com/38882
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>