[LLDB][test] - Fix test after yaml2obj change.

D95354 started to set the sh_link field for SHT_SYMTAB sections.
Previously it was set for symbol tables basing on their names (e.g. ".symtab").

This test now crashes see:
http://lab.llvm.org:8011/#/builders/68/builds/5911

I updated it to restore the old behavior.