v2 stats: write stats at work directory

Stats must be in work dir, as logfiles and pidfiles.
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

stats.c

@@ -134,7 +134,7 @@ void write_stats(int what)
 	} else
 		return;
 
-	fd = open_image(CR_FD_STATS, O_DUMP, name);
+	fd = open_image_at(AT_FDCWD, CR_FD_STATS, O_DUMP, name);
 	if (fd >= 0) {
 		pb_write_one(fd, &stats, PB_STATS);
 		close(fd);