[NFC] Fix compile warnings in llvm/unittests/Object/OffloadingBundleTest.cpp (llvm#3773)

Author: shiltian

llvm/unittests/Object/OffloadingBundleTest.cpp

@@ -53,8 +53,6 @@ toBinary(SmallVectorImpl<char> &Storage, StringRef Yaml) {
 TEST(OffloadingBundleTest, checkExtractOffloadBundleFatBinary) {
 
   // create a Memory Buffer with a fatbin offloading section
-  MemoryBufferRef mbuf;
-  StringRef FileName;
   SmallVector<OffloadBundleEntry>();
   SmallString<0> Storage;
   // Expected<ELFObjectFile<ELF64LE>> ObjOrErr = toBinary<ELF64LE>(Storage, R"(
@@ -69,8 +67,6 @@ TEST(OffloadingBundleTest, checkExtractOffloadBundleFatBinary) {
 
 TEST(OffloadingBundleTest, checkExtractCodeObject) {
   // create a Memory Buffer with a fatbin offloading section
-  MemoryBufferRef mbuf;
-  StringRef FileName;
   SmallVector<OffloadBundleEntry>();
   SmallString<0> Storage;
   // Expected<ELFObjectFile<ELF64LE>> ObjOrErr = toBinary<ELF64LE>(Storage, R"(