SROA.cpp: Fix a warning, [-Wunused-variable]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165309 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/SROA.cpp

@@ -710,6 +710,7 @@ private:
         = MemTransferPartitionMap.insert(std::make_pair(&II, NewIdx)).second;
       assert(Inserted &&
              "Already have intrinsic in map but haven't seen both ends");
+      (void)Inserted;
     }
 
     return true;