Smack: Make the syslog control configurable

Smack: Make the syslog control configurable

The syslog control requires that the calling proccess
have the floor ("_") Smack label. Tizen does not run any
processes except for kernel helpers with the floor label.
This changes allows the admin to configure a specific
label for syslog. The default value is the star ("*")
label, effectively removing the restriction. The value
can be set using smackfs/syslog for anyone who wants
a more restrictive behavior.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[sw0312.kim: backport from mainline commit 00f84f3f2e9d to support non-root user dlog]
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: I030b6a271020c1ff9aa79538afb753fed3d7289e