Reland "[llvm-objcopy] Refactor llvm-objcopy to use reader and writer…

… objects"

I had more unused varibles. This change removes those to get rid of warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323493 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-objcopy/Object.cpp

@@ -698,13 +698,13 @@ ELFReader::ELFReader(StringRef File) {
 }
 
 ElfType ELFReader::getElfType() const {
-  if (auto *o = dyn_cast<ELFObjectFile<ELF32LE>>(Binary.get()))
+  if (isa<ELFObjectFile<ELF32LE>>(Binary.get()))
     return ELFT_ELF32LE;
-  if (auto *o = dyn_cast<ELFObjectFile<ELF64LE>>(Binary.get()))
+  if (isa<ELFObjectFile<ELF64LE>>(Binary.get()))
     return ELFT_ELF64LE;
-  if (auto *o = dyn_cast<ELFObjectFile<ELF32BE>>(Binary.get()))
+  if (isa<ELFObjectFile<ELF32BE>>(Binary.get()))
     return ELFT_ELF32BE;
-  if (auto *o = dyn_cast<ELFObjectFile<ELF64BE>>(Binary.get()))
+  if (isa<ELFObjectFile<ELF64BE>>(Binary.get()))
     return ELFT_ELF64BE;
   llvm_unreachable("Invalid ELFType");
 }