ELF: Move code to emit copyrel to one place. NFC.
ELF: Move code to emit copyrel to one place. NFC.

In this code, we avoid calling needsCopyRel in writeTo because
we called that function already in scanRelocs. Making the same
decision twice is a waste and has a risk of a bug that we get
inconsistent resuts.

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@258430 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld