[CodeGen]: BlockPlacement: Skip extraneous logging.

Move a check for blocks that are not candidates for tail duplication up before
the logging. Reduces logging noise. No non-logging changes intended.

llvm-svn: 294086
diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
index 6be20ab..8a57f00 100644
--- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp
+++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
@@ -2215,13 +2215,13 @@
     BlockChain &Chain, BlockFilterSet *BlockFilter,
     MachineFunction::iterator &PrevUnplacedBlockIt,
     bool &DuplicatedToLPred) {
-
   DuplicatedToLPred = false;
+  if (!shouldTailDuplicate(BB))
+    return false;
+
   DEBUG(dbgs() << "Redoing tail duplication for Succ#"
         << BB->getNumber() << "\n");
 
-  if (!shouldTailDuplicate(BB))
-    return false;
   // This has to be a callback because none of it can be done after
   // BB is deleted.
   bool Removed = false;