doc: Fix the Doxygen section endings

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/core/write_queue.h b/include/osmocom/core/write_queue.h
index 8b896d1..816c036 100644
--- a/include/osmocom/core/write_queue.h
+++ b/include/osmocom/core/write_queue.h
@@ -58,6 +58,6 @@
 int osmo_wqueue_enqueue(struct osmo_wqueue *queue, struct msgb *data);
 int osmo_wqueue_bfd_cb(struct osmo_fd *fd, unsigned int what);
 
-/*! }@ */
+/*! @} */
 
 #endif