Replace "cont" with "cgrp" and other misc renaming

This patch finishes some of the names that got missed in the great
"task containers" -> "control groups" rename. Primarily it renames
the local variable "cont" to "cgrp" in a number of places, and renames
the CONT_* enum members to CGRP_*.

This patch is not intended to have any effect on the generated code;
the output of "objdump -d kernel/cgroup.o" is unchanged.
Signed-off-by: NPaul Menage <menage@google.com>
Acked-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>