Utilities/tar: Open archive file before changing directory

Otherwise the utility will fail to open the archive file because it's
presumably not in the chosen directory.

Userland/Utilities/tar.cpp

@@ -72,11 +72,11 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     }
 
     if (list || extract) {
+        NonnullOwnPtr<Stream> input_stream = TRY(Core::InputBufferedFile::create(TRY(Core::File::open_file_or_standard_stream(archive_file, Core::File::OpenMode::Read))));
+
         if (!directory.is_empty())
             TRY(Core::System::chdir(directory));
 
-        NonnullOwnPtr<Stream> input_stream = TRY(Core::InputBufferedFile::create(TRY(Core::File::open_file_or_standard_stream(archive_file, Core::File::OpenMode::Read))));
-
         if (gzip)
             input_stream = make<Compress::GzipDecompressor>(move(input_stream));