BUG/MINOR: trace: show wall-clock date, not internal date in show activity

Yet another case where "now" was used instead of "date" for a publicly
visible date that was already incorrect and became worse after commit
28360dc ("MEDIUM: clock: force internal time to wrap early after boot").
No backport is needed.
diff --git a/src/flt_trace.c b/src/flt_trace.c
index 5aabcb2..bbadfe2 100644
--- a/src/flt_trace.c
+++ b/src/flt_trace.c
@@ -43,7 +43,7 @@
 	do {									\
 		if (!(conf->flags & TRACE_F_QUIET))				\
 			fprintf(stderr, "%d.%06d [%-20s] " fmt "\n",		\
-				(int)now.tv_sec, (int)now.tv_usec, (conf)->name,\
+				(int)date.tv_sec, (int)date.tv_usec, (conf)->name,\
 				##__VA_ARGS__);					\
 	} while (0)
 
@@ -51,7 +51,7 @@
 	do {												\
 		if (!(conf->flags & TRACE_F_QUIET))							\
 			fprintf(stderr, "%d.%06d [%-20s] [strm %p(%x) 0x%08x 0x%08x] " fmt "\n",	\
-				(int)now.tv_sec, (int)now.tv_usec, (conf)->name,			\
+				(int)date.tv_sec, (int)date.tv_usec, (conf)->name,			\
 				strm, (strm ? ((struct stream *)strm)->uniq_id : ~0U),			\
 				(strm ? strm->req.analysers : 0), (strm ? strm->res.analysers : 0),	\
 				##__VA_ARGS__);								\