Change GetPortableCode result from reference to pointer

(cherry picked from commit 93a5497a5ebe91e2798f8f7c71b177df1218a68c)

Change-Id: I725ce6389b1960d487b4111417627836ae96fe9d
diff --git a/compiler/elf_writer_mclinker.cc b/compiler/elf_writer_mclinker.cc
index e56f5f8..3c3d09e 100644
--- a/compiler/elf_writer_mclinker.cc
+++ b/compiler/elf_writer_mclinker.cc
@@ -265,7 +265,7 @@
   added_symbols_.Put(&symbol, &symbol);
 
   // Add input to supply code for symbol
-  const std::vector<uint8_t>& code = compiled_code.GetPortableCode();
+  const std::vector<uint8_t>* code = compiled_code.GetPortableCode();
   // TODO: ownership of code_input?
   // TODO: why does IRBuilder::ReadInput take a non-const pointer?
   mcld::Input* code_input = ir_builder_->ReadInput(symbol,