qemu: delete unused QEMUD_CPUMASK_LEN macro
qemu: delete unused QEMUD_CPUMASK_LEN macro

Unused as of:
commit f136b83139c63f20de0df3285d9e82df2fb97bfc
    qemu: Rework setting process affinity

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Reviewed-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>

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