doc: Fix the Doxygen section endings

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/src/write_queue.c b/src/write_queue.c
index 9ddc3af..cef40f8 100644
--- a/src/write_queue.c
+++ b/src/write_queue.c
@@ -115,4 +115,4 @@
 	queue->bfd.when &= ~BSC_FD_WRITE;
 }
 
-/*! }@ */
+/*! @} */