BUG/MINOR: dumpstats: fix write to global chunk

This just happens to work as it is the correct chunk, but should be whatever
gets passed in as argument.

Signed-off-by: Conrad Hoffmann <conrad@soundcloud.com>
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 7e2a1d2..da26f80 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -3211,7 +3211,7 @@
 		if (!chunk_strcat(out, ","))
 			return 0;
 	}
-	chunk_strcat(&trash, "\n");
+	chunk_strcat(out, "\n");
 	return 1;
 }