qemu: Rename path-building functions
qemu: Rename path-building functions

Using the word "create" can give users the impression that disk
operations will be performed, when in reality all these functions
do is string formatting.

Follow the naming convention established by virBuildPath(),
virFileBuildPath() and virPidFileBuildPath().

Signed-off-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>

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