qemu_cgroup: Introduce qemuCgroupAllowDevicesPaths()
qemu_cgroup: Introduce qemuCgroupAllowDevicesPaths()

We have qemuCgroupAllowDevicePath() which sets up devices
controller for just one path. And if we have more paths we have
to call it in a loop. So far, we have just one such place, but
soon we'll have another one (for SGX memory). Separate the loop
into its own function so that it can be reused.

And while at it, move setting the default set of devices as the
first thing, right after all devices are disallowed.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Martin Kletzander <e82f23e74d43760279ebcc505dac4ae70d5627d0@redhat.com>

libvirt/libvirt,olafhering/libvirt,jfehlig/libvirt,crobinso/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,olafhering/libvirt,crobinso/libvirt,crobinso/libvirt,libvirt/libvirt,zippy2/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,zippy2/libvirt,olafhering/libvirt,jfehlig/libvirt,libvirt/libvirt