Modernise code to use override specifier

Generated by clang-tidy.

Test: m checkbuild
Change-Id: I8e23da6b8af31b291be2eefe9937ca222ea8a8c3
diff --git a/tests/sys_resource_test.cpp b/tests/sys_resource_test.cpp
index 0b6b6ef..b1e8b1a 100644
--- a/tests/sys_resource_test.cpp
+++ b/tests/sys_resource_test.cpp
@@ -30,7 +30,7 @@
 
 class SysResourceTest : public ::testing::Test {
  protected:
-  virtual void SetUp() {
+  void SetUp() override {
     ASSERT_EQ(0, getrlimit(RLIMIT_CORE, &l32_));
     ASSERT_EQ(0, getrlimit64(RLIMIT_CORE, &l64_));
     ASSERT_EQ(0, prlimit(0, RLIMIT_CORE, nullptr, &pr_l32_));