Modernise code to use override specifier

Generated by clang-tidy.

Test: m checkbuild
Change-Id: I8e23da6b8af31b291be2eefe9937ca222ea8a8c3
diff --git a/tests/sys_ptrace_test.cpp b/tests/sys_ptrace_test.cpp
index 9b3dba0..90539fe 100644
--- a/tests/sys_ptrace_test.cpp
+++ b/tests/sys_ptrace_test.cpp
@@ -402,7 +402,7 @@
     }
   }
 
-  ~PtraceResumptionTest() {
+  ~PtraceResumptionTest() override {
   }
 
   void AssertDeath(int signo);