Fix errors in comments from William Gandler.

Change-Id: I1c1f1f7bdc4a1748994c3b43e72270b88f2a2b96

internal/ceres/linear_least_squares_problems.cc

diff --git a/internal/ceres/linear_least_squares_problems.cc b/internal/ceres/linear_least_squares_problems.cc
index 299051c..73787d6 100644
--- a/internal/ceres/linear_least_squares_problems.cc
+++ b/internal/ceres/linear_least_squares_problems.cc
@@ -161,7 +161,7 @@
 
       S = [ 42.3419  -1.4000  -11.5806
             -1.4000   2.6000    1.0000
-            11.5806   1.0000   31.1935]
+           -11.5806   1.0000   31.1935]
 
       r = [ 4.3032
             5.4000

internal/ceres/small_blas_test.cc

diff --git a/internal/ceres/small_blas_test.cc b/internal/ceres/small_blas_test.cc
index d0312ec..2dde17e 100644
--- a/internal/ceres/small_blas_test.cc
+++ b/internal/ceres/small_blas_test.cc
@@ -400,7 +400,7 @@
           b.data(),
           c_minus.data());
       EXPECT_NEAR((c_minus_ref - c_minus).norm(), 0.0, kTolerance)
-          << "c += A * b \n"
+          << "c -= A * b \n"
           << "c_ref : \n" << c_minus_ref << "\n"
           << "c: \n" << c_minus;
 
@@ -410,7 +410,7 @@
           b.data(),
           c_assign.data());
       EXPECT_NEAR((c_assign_ref - c_assign).norm(), 0.0, kTolerance)
-          << "c += A * b \n"
+          << "c = A * b \n"
           << "c_ref : \n" << c_assign_ref << "\n"
           << "c: \n" << c_assign;
       // clang-format on
@@ -455,7 +455,7 @@
           b.data(),
           c_minus.data());
       EXPECT_NEAR((c_minus_ref - c_minus).norm(), 0.0, kTolerance)
-          << "c += A' * b \n"
+          << "c -= A' * b \n"
           << "c_ref : \n" << c_minus_ref << "\n"
           << "c: \n" << c_minus;
 
@@ -465,7 +465,7 @@
           b.data(),
           c_assign.data());
       EXPECT_NEAR((c_assign_ref - c_assign).norm(), 0.0, kTolerance)
-          << "c += A' * b \n"
+          << "c = A' * b \n"
           << "c_ref : \n" << c_assign_ref << "\n"
           << "c: \n" << c_assign;
       // clang-format on