[ELF] Refactor target error messages

Differential revision: https://reviews.llvm.org/D27097

llvm-svn: 288114
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index e4536ef..4a723d5 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -249,6 +249,7 @@
 }
 
 template <class ELFT> void OutputSection<ELFT>::writeTo(uint8_t *Buf) {
+  Loc = Buf;
   if (uint32_t Filler = Script<ELFT>::X->getFiller(this->Name))
     fill(Buf, this->Size, Filler);