[SystemZ] Use "auto" for cast results

No functional change intended.

llvm-svn: 203106
diff --git a/llvm/lib/Target/SystemZ/SystemZConstantPoolValue.cpp b/llvm/lib/Target/SystemZ/SystemZConstantPoolValue.cpp
index 6c70811..19cec21 100644
--- a/llvm/lib/Target/SystemZ/SystemZConstantPoolValue.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZConstantPoolValue.cpp
@@ -43,7 +43,7 @@
   for (unsigned I = 0, E = Constants.size(); I != E; ++I) {
     if (Constants[I].isMachineConstantPoolEntry() &&
         (Constants[I].getAlignment() & AlignMask) == 0) {
-      SystemZConstantPoolValue *ZCPV =
+      auto *ZCPV =
         static_cast<SystemZConstantPoolValue *>(Constants[I].Val.MachineCPVal);
       if (ZCPV->GV == GV && ZCPV->Modifier == Modifier)
         return I;