Mark death tests properly.

A few death tests are not set to silence tombstones, so fix
all of those occurrences.

Test: Ran all death tests and no tombstones generated.
Change-Id: If2b54b1a3432edbd54076439d40527d966607f70
diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index b3a296d..b2195e7 100644
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -3310,7 +3310,7 @@
 #endif
 }
 
-TEST(STDIO_TEST, snprintf_invalid_w_width) {
+TEST_F(STDIO_DEATHTEST, snprintf_invalid_w_width) {
 #if defined(__BIONIC__)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wformat-invalid-specifier"
@@ -3323,7 +3323,7 @@
 #endif
 }
 
-TEST(STDIO_TEST, swprintf_invalid_w_width) {
+TEST_F(STDIO_DEATHTEST, swprintf_invalid_w_width) {
 #if defined(__BIONIC__)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wformat-invalid-specifier"
@@ -3459,7 +3459,7 @@
 #endif
 }
 
-TEST(STDIO_TEST, snprintf_invalid_wf_width) {
+TEST_F(STDIO_DEATHTEST, snprintf_invalid_wf_width) {
 #if defined(__BIONIC__)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wformat"
@@ -3473,7 +3473,7 @@
 #endif
 }
 
-TEST(STDIO_TEST, swprintf_invalid_wf_width) {
+TEST_F(STDIO_DEATHTEST, swprintf_invalid_wf_width) {
 #if defined(__BIONIC__)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wformat"
@@ -3572,7 +3572,7 @@
 #endif
 }
 
-TEST(STDIO_TEST, sscanf_invalid_w_or_wf_width) {
+TEST_F(STDIO_DEATHTEST, sscanf_invalid_w_or_wf_width) {
 #if defined(__BIONIC__)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wformat"
@@ -3672,7 +3672,7 @@
 #endif
 }
 
-TEST(STDIO_TEST, swscanf_invalid_w_or_wf_width) {
+TEST_F(STDIO_DEATHTEST, swscanf_invalid_w_or_wf_width) {
 #if defined(__BIONIC__)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wformat"