Increase tolerance in small_blas_test.cc

Change-Id: I7b8460bec65e56029d01c293e83743e99a57d10c
diff --git a/internal/ceres/small_blas_test.cc b/internal/ceres/small_blas_test.cc
index 6f819c4..0d6dd73 100644
--- a/internal/ceres/small_blas_test.cc
+++ b/internal/ceres/small_blas_test.cc
@@ -38,7 +38,7 @@
 namespace ceres {
 namespace internal {
 
-const double kTolerance = 3.0 * std::numeric_limits<double>::epsilon();
+const double kTolerance = 5.0 * std::numeric_limits<double>::epsilon();
 
 TEST(BLAS, MatrixMatrixMultiply) {
   const int kRowA = 3;