unit-tests: cleanup traces after testing

Otherwise it appears to be a leak:

==612637== 11,264 bytes in 1 blocks are still reachable in loss record 1 of 1
==612637==    at 0x484D953: calloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==612637==    by 0x1301F2: trace_init (trace.c:153)
==612637==    by 0x13065D: trace_span_start (trace.c:263)
==612637==    by 0x173968: db_open_ (utils.c:367)
==612637==    by 0x17AE43: create_test_wallet (run-wallet.c:1313)
==612637==    by 0x17C726: test_shachain_crud (run-wallet.c:1548)
==612637==    by 0x18300E: main (run-wallet.c:2329)

Changelog-None

plugins/bkpr/test/run-bkpr_db.c

@@ -323,5 +323,6 @@ int main(int argc, char *argv[])
 
 	tal_free(plugin);
 	common_shutdown();
+	trace_cleanup();
 	return !ok;
 }

plugins/bkpr/test/run-recorder.c

@@ -1430,5 +1430,6 @@ int main(int argc, char *argv[])
 
 	tal_free(plugin);
 	common_shutdown();
+	trace_cleanup();
 	return !ok;
 }

wallet/test/run-db.c

@@ -1,5 +1,5 @@
 #include "config.h"
-  #include <lightningd/log.h>
+#include <lightningd/log.h>
 
 static void db_log_(struct logger *log UNUSED, enum log_level level UNUSED, const struct node_id *node_id UNUSED, bool call_notifier UNUSED, const char *fmt UNUSED, ...)
 {
@@ -544,5 +544,6 @@ int main(int argc, char *argv[])
 
 	tal_free(ld);
 	common_shutdown();
+	trace_cleanup();
 	return !ok;
 }

wallet/test/run-wallet.c

@@ -2341,6 +2341,7 @@ int main(int argc, const char *argv[])
 	 * database. */
 	if (ok) {
 		common_shutdown();
+		trace_cleanup();
 	}
 	return !ok;
 }