Now that the SELinux NetLabel "base SID" is always the netmsg initial SID we
can do a big optimization - caching the SID and not just the MLS attributes.
This not only saves a lot of per-packet memory allocations and copies but it
has a nice side effect of removing a chunk of code.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>