JFS: Implement jfs_init_security

This atomically initializes the security xattr when an object is created

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>

diff --cc fs/jfs/jfs_xattr.h
Simple merge

diff --cc fs/jfs/namei.c
Simple merge

diff --cc fs/jfs/xattr.c
Simple merge