Combine the two build_iso_path* functions into build_iso_path.
Combine the two build_iso_path* functions into build_iso_path.

This makes it simpler and easier to deal with.

Signed-off-by: Chris Lalancette <281cd07d7578d97c83271fbbf2faddb83ab3791c@gmail.com>

clalancette/pycdlib,clalancette/pyiso