Utility timestamp_ns() fix (#175)

* Update lib/common/utility.*

- fix timestamp_ns()

* Update samples/**/CMakeLists.txt

- fail test if exception thrown

* source formatting (clang-format v11) (#176)

Co-authored-by: jrmadsen <jrmadsen@users.noreply.github.com>

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

samples/api_buffered_tracing/CMakeLists.txt

@@ -57,4 +57,5 @@ set_tests_properties(
         "samples"
         ENVIRONMENT
         "${ROCPROFILER_MEMCHECK_PRELOAD_ENV};HSA_TOOLS_LIB=$<TARGET_FILE:rocprofiler::rocprofiler>"
-    )
+        FAIL_REGULAR_EXPRESSION
+        "threw an exception")