ocfs2: trusted xattr missing CAP_SYS_ADMIN check

ocfs2: trusted xattr missing CAP_SYS_ADMIN check

The trusted extended attributes are only visible to the process which
hvae CAP_SYS_ADMIN capability but the check is missing in ocfs2
xattr_handler trusted list.  The check is important because this will be
used for implementing mechanisms in the userspace for which other
ordinary processes should not have access to.

Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Taesoo kim <taesoo@gatech.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 0f5e7b41f91814447defc34e915fc5d6e52266d9)

Orabug: 24939243

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>