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/sys_msg_test.cpp b/tests/sys_msg_test.cpp
index 8b3623e..200f654 100644
--- a/tests/sys_msg_test.cpp
+++ b/tests/sys_msg_test.cpp
@@ -35,8 +35,7 @@
 
 TEST(sys_msg, smoke) {
   if (msgctl(-1, IPC_STAT, nullptr) == -1 && errno == ENOSYS) {
-    GTEST_LOG_(INFO) << "no <sys/msg.h> support in this kernel\n";
-    return;
+    GTEST_SKIP() << "no <sys/msg.h> support in this kernel";
   }
 
   // Create a queue.