Fix uninitialized variable warning. NFCI.

llvm-svn: 372508
diff --git a/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp b/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
index f792f40..98dfd0a 100644
--- a/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
+++ b/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
@@ -970,7 +970,7 @@
       break;
     }
 
-    SDNode *Res;
+    SDNode *Res = nullptr;
 
     // If we have a signed 10 bit integer, we can splat it directly.
     //