From: Rusty Russell <rusty@rustcorp.com.au>

PowerPC64 ABI has ".funcname" (the actual function) and "funcname" (the
function descriptor) and we strip off the dots in "dedotify" called from
module_frob_arch_sections().  We need to also de-dotify the corresponding
names in the __version section.

Actually has nothing to do with __down, it's just that we only print the
first symbol whose version is missing.