base: Remove the string logging from CHECK().

sandbox/linux/services/credentials_unittest.cc

Index: sandbox/linux/services/credentials_unittest.cc
diff --git a/sandbox/linux/services/credentials_unittest.cc b/sandbox/linux/services/credentials_unittest.cc
index 41c04bbcc292df674339209539d71bc2f62174a2..bec47615aaaced2b4dd38aea57dea94e20c18d9f 100644
--- a/sandbox/linux/services/credentials_unittest.cc
+++ b/sandbox/linux/services/credentials_unittest.cc
@@ -130,8 +130,8 @@ SANDBOX_TEST(Credentials, NestedUserNS) {
   // As of 3.12, the kernel has a limit of 32. See create_user_ns().
   const int kNestLevel = 10;
   for (int i = 0; i < kNestLevel; ++i) {
-    CHECK(NewUserNSCycle()) << "Creating new user NS failed at iteration "
-                                  << i << ".";
+    // Creating new user NS failed at iteration |i|.
+    CHECK(NewUserNSCycle());
   }
 }