tests: respect naming conventions and improve nesting of some test suites

Change-Id: I65af858bc6d10197c6ee11111fa9f7c1faa617ef
Refs: #2497
diff --git a/tests/daemon/fw/retx-suppression.t.cpp b/tests/daemon/fw/retx-suppression.t.cpp
index 7013aef..604dfb1 100644
--- a/tests/daemon/fw/retx-suppression.t.cpp
+++ b/tests/daemon/fw/retx-suppression.t.cpp
@@ -36,7 +36,8 @@
 
 using namespace nfd::tests;
 
-BOOST_FIXTURE_TEST_SUITE(FwRetxSuppression, UnitTestTimeFixture)
+BOOST_AUTO_TEST_SUITE(Fw)
+BOOST_FIXTURE_TEST_SUITE(TestRetxSuppression, UnitTestTimeFixture)
 
 BOOST_AUTO_TEST_CASE(Fixed)
 {
@@ -155,7 +156,8 @@
   // suppression interval is 100ms, until 304ms
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_SUITE_END() // TestRetxSuppression
+BOOST_AUTO_TEST_SUITE_END() // Fw
 
 } // namespace tests
 } // namespace fw