[ELF] Loose a condition for relocation with a symbol

Deleted code was introduced as a work around for a bug in the gold linker
(http://sourceware.org/PR16794). Test case that was given as a reason for
this part of code, the one on previous link, now works for the gold.
This condition is too strict and when a code is compiled with debug info
it forces generation of numerous relocations with symbol for architectures
that do not have relocation addend.

Reviewers: arsenm, espindola

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D64327

llvm-svn: 365618