[lld] r250555 - [ELF2] getLocalRelTarget should handle R_PPC64_TOC directly

[Rafael Espíndola via llvm-commits]

> When why does the code in RelocationSection<ELFT>::writeTo have this?
>
>   bool IsMips64EL = Relocs[0].C.getFile()->getObj().isMips64EL();
>
> I thought this might return a different result from File.getObj().isMips64EL() [but then forgot to ask].

The code is there just to factor out IsMips64EL. The value will be the
same for every reloc, so this puts the boring code out of the way.

Cheers,
Rafael