Revert "[Sanitizers][Darwin] In DlAddrSymbolizer, return only the module file...

Revert "[Sanitizers][Darwin] In DlAddrSymbolizer, return only the module file name instead of the comlpete module path during symbolication."

The commit broke asan_symbolize.py script on Darwin which depended on
using the complete module path to symolize crash traces offline.

This reverts commit f6ea869f.

rdar://110487521