[PATCH] selinux: eliminate selinux_task_ctxid

Eliminate selinux_task_ctxid since it duplicates selinux_task_get_sid.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>