qemu_ns: Allow /dev/mapper/control for PR
qemu_ns: Allow /dev/mapper/control for PR

If qemu-pr-helper is compiled with multipath support the first
thing it does is open /dev/mapper/control. Since we're going
to be running it inside qemu namespace we need to create it
there. Unfortunately, we don't know if it was compiled with or
without multipath so we have to create it anyway.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

andreabolognani/libvirt,libvirt/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,jardasgit/libvirt,eskultety/libvirt,nertpinx/libvirt,zippy2/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,libvirt/libvirt,crobinso/libvirt,nertpinx/libvirt,jardasgit/libvirt,libvirt/libvirt,jfehlig/libvirt,eskultety/libvirt,olafhering/libvirt,olafhering/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,jardasgit/libvirt,eskultety/libvirt,crobinso/libvirt,zippy2/libvirt,jfehlig/libvirt,zippy2/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,eskultety/libvirt,libvirt/libvirt,crobinso/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,jardasgit/libvirt,olafhering/libvirt,nertpinx/libvirt,jardasgit/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jfehlig/libvirt