LU-12275 sec: ldiskfs not aware of client-side encryption

LU-12275 sec: ldiskfs not aware of client-side encryption

In osd-ldiskfs, always remove S_ENCRYPTED from inode flags,
because ldiskfs must not be aware of client-side encryption status.
This info is just stored into LMA so that it can be forwared to client
side.

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: Ief08c059b04b8c7349d725b50b2094183eabc4d3
Reviewed-on: https://review.whamcloud.com/39558
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Wang Shilong <wshilong@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>