bionic tests: use GTEST_SKIP.

Also be a bit more to the point in our messages, focusing on "why" not
"what".

Test: ran tests
Change-Id: I297806c7a102bd52602dcd2fcf7a2cd34aba3a11
diff --git a/tests/sched_test.cpp b/tests/sched_test.cpp
index 9184026..9309a7f 100644
--- a/tests/sched_test.cpp
+++ b/tests/sched_test.cpp
@@ -47,7 +47,7 @@
 // See https://sourceware.org/bugzilla/show_bug.cgi?id=10311 for more details.
 TEST(sched, clone) {
   // In order to enumerate all possible tests for CTS, create an empty test.
-  GTEST_LOG_(INFO) << "This test does nothing.\n";
+  GTEST_SKIP() << "glibc is broken";
 }
 #endif