virdnsmasq: Join dnsmasqCapsNewEmpty() and dnsmasqCapsNewFromBinary()
virdnsmasq: Join dnsmasqCapsNewEmpty() and dnsmasqCapsNewFromBinary()

After previous cleanups, there's just one caller of
dnsmasqCapsNewEmpty() and it is dnsmasqCapsNewFromBinary().
And the former is pretty short. Therefore, it is not necessary
for the code to live in two separate functions. Dissolve the
former in the latter.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>

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