Clang warned about a dead assignment. In the process, I noticed
that we are only using the function for a bool value. I audited
all other callers in qemu_{migration,cgroup,driver,hotplug), and
all were making the call in a bool context.
Also, do bounds checking on the argument.
* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Delete dead
assignment.
(qemuCgroupControllerActive): Change return type to bool.
* src/qemu/qemu_cgroup.h (qemuCgroupControllerActive): Likewise.
The QEMU driver file is far too large. Move all the cgroup
helper code out into a separate file. No functional change.
* src/qemu/qemu_cgroup.c, src/qemu/qemu_cgroup.h,
src/Makefile.am: Add cgroup helper file
* src/qemu/qemu_driver.c: Delete cgroup code