[ObjectYAML] - Do not use auto. NFC.

Using 'auto' when the type is not obvious is undesired.

(it is just a test commit actually)
diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index dae3f39..d5cdb85 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -494,7 +494,7 @@
   Ret.resize(Symbols.size() + 1);
 
   size_t I = 0;
-  for (const auto &Sym : Symbols) {
+  for (const ELFYAML::Symbol &Sym : Symbols) {
     Elf_Sym &Symbol = Ret[++I];
 
     // If NameIndex, which contains the name offset, is explicitly specified, we