virdevmapper.c: Join two WITH_DEVMAPPER sections together
virdevmapper.c: Join two WITH_DEVMAPPER sections together

There are two distinct WITH_DEVMAPPER sections in the file, for
different functions each. Rearrange the code to make some of
future commits smaller.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

olafhering/libvirt,olafhering/libvirt,jardasgit/libvirt,jardasgit/libvirt,libvirt/libvirt,nertpinx/libvirt,zippy2/libvirt,nertpinx/libvirt,crobinso/libvirt,crobinso/libvirt,jfehlig/libvirt,jardasgit/libvirt,jfehlig/libvirt,crobinso/libvirt,jardasgit/libvirt,jfehlig/libvirt,nertpinx/libvirt,crobinso/libvirt,zippy2/libvirt,zippy2/libvirt,libvirt/libvirt,olafhering/libvirt,jardasgit/libvirt,zippy2/libvirt,libvirt/libvirt,jfehlig/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,libvirt/libvirt