Fix repeated SpMV Benchmark

Change-Id: I9180cb548a865665f74e1b082c11741a1b87b5ab

internal/ceres/spmv_benchmark.cc

diff --git a/internal/ceres/spmv_benchmark.cc b/internal/ceres/spmv_benchmark.cc
index 0f475be..0bd1e43 100644
--- a/internal/ceres/spmv_benchmark.cc
+++ b/internal/ceres/spmv_benchmark.cc
@@ -416,7 +416,7 @@
   CHECK_NE(sum, 0.0);
 }
 
-BENCHMARK(BM_CudaLeftMultiplyAndAccumulateBA);
+BENCHMARK(BM_CudaLeftMultiplyAndAccumulateUnstructured);
 
 #endif