[ELF] -r: fix R_*_NONE to section symbols on Elf*_Rel targets

On Elf*_Rel targets, for a relocation to a section symbol, an R_ABS is
added which will be used by relocateOne() to compute the implicit
addend.

Addends of R_*_NONE should be ignored, so don't emit an R_ABS.

This fixes crashes on X86 and ARM because their relocateOne() do not
handle R_*_NONE.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D62052

llvm-svn: 361036