Fix a use after free. An instruction can't be both an intrinsic call and a fence.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136319 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LowerAtomic.cpp b/lib/Transforms/Scalar/LowerAtomic.cpp
index 7f4d9e9..0954f77 100644
--- a/lib/Transforms/Scalar/LowerAtomic.cpp
+++ b/lib/Transforms/Scalar/LowerAtomic.cpp
@@ -132,7 +132,7 @@
         Instruction *Inst = DI++;
         if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst))
           Changed |= LowerAtomicIntrinsic(II);
-        if (FenceInst *FI = dyn_cast<FenceInst>(Inst))
+        else if (FenceInst *FI = dyn_cast<FenceInst>(Inst))
           Changed |= LowerFenceInst(FI);
       }
       return Changed;