Fix a bunch of -Wpessimizing-move issues.

Thanks to Rui for pointing out this warning was firing.

llvm-svn: 264977
diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
index 0ec7a40..5eb5924 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
@@ -779,7 +779,7 @@
     // Object files have one unnamed segment which holds all sections.
     if (_is64) {
      if (auto ec = writeSingleSegmentLoadCommand<MachO64Trait>(lc))
-       return std::move(ec);
+       return ec;
     } else {
       if (auto ec = writeSingleSegmentLoadCommand<MachO32Trait>(lc))
         return std::move(ec);