Re: [libvirt] [PATCH v1 08/40] util: cgroup: define cleanup function using VIR_DEFINE_AUTOPTR_FUNC

Using the new VIR_DEFINE_AUTOPTR_FUNC macro defined in src/util/viralloc.h, define a new wrapper around an existing cleanup function which will be called when a variable declared with VIR_AUTOPTR macro goes out of scope. Also, drop the redundant viralloc.h include, since that has moved from the source module into the header. When a variable of type virCgroupPtr is declared using VIR_AUTOPTR, the function virCgroupFree will be run automatically on it when it goes out of scope. This commit also adds an intermediate typedef for virCgroup type for use with the cleanup macros by renaming the struct in src/util/vircgrouppriv.h from virCgroup to _virCgroup.