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/__aeabi_read_tp_test.cpp b/tests/__aeabi_read_tp_test.cpp
index 6974658..7209a75 100644
--- a/tests/__aeabi_read_tp_test.cpp
+++ b/tests/__aeabi_read_tp_test.cpp
@@ -38,6 +38,6 @@
 #if defined(__arm__)
   ASSERT_EQ(__aeabi_read_tp(), static_cast<void*>(__get_tls()));
 #else
-  GTEST_LOG_(INFO) << "__aeabi_read_tp is only available on arm32.\n";
+  GTEST_SKIP() << "__aeabi_read_tp is only available on arm32";
 #endif
 }