[tools] Remove unused local variables (NFC) (llvm#142880)

Author: kazutakahirata

clang/tools/clang-installapi/Options.cpp

@@ -763,7 +763,6 @@ getInterfaceFile(const StringRef Filename) {
     return errorCodeToError(std::move(Err));
 
   auto Buffer = std::move(*BufferOrErr);
-  std::unique_ptr<InterfaceFile> IF;
   switch (identify_magic(Buffer->getBuffer())) {
   case file_magic::macho_dynamically_linked_shared_lib:
   case file_magic::macho_dynamically_linked_shared_lib_stub:

clang/tools/clang-offload-packager/ClangOffloadPackager.cpp

@@ -106,7 +106,6 @@ static Error bundleImages() {
     // Permit using multiple instances of `file` in a single string.
     for (auto &File : llvm::split(Args["file"], ",")) {
       OffloadBinary::OffloadingImage ImageBinary{};
-      std::unique_ptr<llvm::MemoryBuffer> DeviceImage;
 
       llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> ObjectOrErr =
           llvm::MemoryBuffer::getFileOrSTDIN(File);