Fix some bionic death tests.

These were creating tombstones and spewing to the log.

You need TEST_F() rather than TEST(), and the modern style is apparently
to use `using` rather than an empty subclass.

Bug: http://b/180605583
Test: run tests, check logcat
Change-Id: I1e639d34854aeff6f042c24643b769a6bcfab877
diff --git a/tests/cfi_test.cpp b/tests/cfi_test.cpp
index e0ae3af..d3cd8d1 100644
--- a/tests/cfi_test.cpp
+++ b/tests/cfi_test.cpp
@@ -35,6 +35,8 @@
 size_t __cfi_shadow_size();
 }
 
+using cfi_test_DeathTest = BionicDeathTest;
+
 static void f() {}
 
 static void test_cfi_slowpath_with_alloc() {
@@ -45,7 +47,7 @@
   }
 }
 
-TEST(cfi_test, basic) {
+TEST_F(cfi_test_DeathTest, basic) {
 #if defined(__BIONIC__)
   void* handle;
   handle = dlopen("libcfi-test.so", RTLD_NOW | RTLD_LOCAL);