Make future patches smaller by matching a sane header listing in
the first place.  No semantic change.

* src/util/vircgroup.h: Move free next to new, and controller
functions next to each other.
* src/util/vircgroup.c (virCgroupFree, virCgroupHasController)
(virCgroupPathOfController, virCgroupRemoveRecursively)
(virCgroupRemove): Sort implementation to be closer to header.
Signed-off-by: NEric Blake <eblake@redhat.com>