Make out arguments non-reference types.

Also, tidy some portable related code.

Change-Id: I67c8aa52eef8b556ca117ecda1b1e75465ba06a5
diff --git a/compiler/elf_writer.cc b/compiler/elf_writer.cc
index 6db3fa1..ccc26a1 100644
--- a/compiler/elf_writer.cc
+++ b/compiler/elf_writer.cc
@@ -30,12 +30,7 @@
 
 namespace art {
 
-ElfWriter::ElfWriter(const CompilerDriver& driver, File* elf_file)
-  : compiler_driver_(&driver), elf_file_(elf_file) {}
-
-ElfWriter::~ElfWriter() {}
-
-Elf32_Addr ElfWriter::GetOatDataAddress(ElfFile* elf_file) {
+uint32_t ElfWriter::GetOatDataAddress(ElfFile* elf_file) {
   Elf32_Addr oatdata_address = elf_file->FindSymbolAddress(SHT_DYNSYM,
                                                            "oatdata",
                                                            false);