Nullability check for stdlib module.

Bugs: b/245972273
Test: None

Change-Id: Ib33a5359a924c21888f268158c4d7f824740dd55
diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index 5fce5b8..2a36460 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -294,10 +294,13 @@
 }
 
 TEST(UNISTD_TEST, setenv_EINVAL) {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnonnull"
   EXPECT_EQ(-1, setenv(nullptr, "value", 0));
   EXPECT_EQ(EINVAL, errno);
   EXPECT_EQ(-1, setenv(nullptr, "value", 1));
   EXPECT_EQ(EINVAL, errno);
+#pragma clang diagnostic pop
   EXPECT_EQ(-1, setenv("", "value", 0));
   EXPECT_EQ(EINVAL, errno);
   EXPECT_EQ(-1, setenv("", "value", 1));