Fixed problem_test(Failed on Windows at least). The parantheses made the regex invalid.

Change-Id: I3318149918eee22b003af6b9effba6aa5cc9f970

internal/ceres/problem_test.cc

diff --git a/internal/ceres/problem_test.cc b/internal/ceres/problem_test.cc
index 6ad56a5..4507dfa 100644
--- a/internal/ceres/problem_test.cc
+++ b/internal/ceres/problem_test.cc
@@ -139,7 +139,7 @@
   // UnaryCostFunction takes only one parameter, but two are passed.
   EXPECT_DEATH_IF_SUPPORTED(
       problem.AddResidualBlock(new UnaryCostFunction(2, 3), NULL, x, y),
-      "parameter_blocks.size()");
+      "parameter_blocks.size");
 }
 
 TEST(Problem, AddResidualWithDifferentSizesOnTheSameVariableDies) {