Add missing error message propagation to ElfFile::SetMap

Change-Id: I085e23cd4728e10a7efca3586270c6cffed9e8d4
diff --git a/runtime/elf_file.h b/runtime/elf_file.h
index b025137..f8c235d 100644
--- a/runtime/elf_file.h
+++ b/runtime/elf_file.h
@@ -122,7 +122,7 @@
 
   bool Setup(File* file, bool writable, bool program_header_only, std::string* error_msg);
 
-  bool SetMap(MemMap* map);
+  bool SetMap(MemMap* map, std::string* error_msg);
 
   byte* GetProgramHeadersStart();
   byte* GetSectionHeadersStart();