Refactor AppendToFile and WriteFileDescriptor

third_party/zlib/google/zip_reader.cc

Index: third_party/zlib/google/zip_reader.cc
diff --git a/third_party/zlib/google/zip_reader.cc b/third_party/zlib/google/zip_reader.cc
index 80b60b3166c629ef3700f226a8c8f4be97089bad..339eb1141c7b4e2103e60324b3ff150b0b7bda91 100644
--- a/third_party/zlib/google/zip_reader.cc
+++ b/third_party/zlib/google/zip_reader.cc
@@ -331,8 +331,7 @@ bool ZipReader::ExtractCurrentEntryToFd(const int fd) {
       break;
     } else if (num_bytes_read > 0) {
       // Some data is read. Write it to the output file descriptor.
-      if (num_bytes_read !=
-          base::WriteFileDescriptor(fd, buf, num_bytes_read)) {
+      if (!base::WriteFileDescriptor(fd, buf, num_bytes_read)) {
         success = false;
         break;
       }