Undo accidental changes to build-prebuilts.sh

I7f875ef0d42574fabb11c0e51621d28da6167d51 accidentally included in
progress features unrelated to the renamed musl sysroots, undo them.

Test: build-prebuilts.sh
Change-Id: Ia689714a16b9b0b33356b9cab1dcf6c44074f234
1 file changed