[Utils] Fix a warning

This patch fixes:

  llvm/lib/Transforms/Utils/SplitModuleByCategory.cpp:321:14: error:
  moving a temporary object prevents copy elision
  [-Werror,-Wpessimizing-move]

Author: kazutakahirata

llvm/lib/Transforms/Utils/SplitModuleByCategory.cpp

@@ -318,6 +318,6 @@ void llvm::splitModuleTransitiveFromEntryPoints(
   ModuleSplitter Splitter(std::move(M), std::move(Groups));
   while (Splitter.hasMoreSplits()) {
     ModuleDesc MD = Splitter.getNextSplit();
-    Callback(std::move(MD.releaseModule()));
+    Callback(MD.releaseModule());
   }
 }