Fix typo.

llvm-svn: 37577
diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp
index 40a7143..87340d3 100644
--- a/llvm/lib/CodeGen/IfConversion.cpp
+++ b/llvm/lib/CodeGen/IfConversion.cpp
@@ -383,7 +383,7 @@
     return;
 
   // First analyze the end of BB branches.
-  BBI.TrueBB = BBI.FalseBB;
+  BBI.TrueBB = BBI.FalseBB = NULL;
   BBI.BrCond.clear();
   BBI.IsBrAnalyzable =
     !TII->AnalyzeBranch(*BBI.BB, BBI.TrueBB, BBI.FalseBB, BBI.BrCond);