doc: Fix the Doxygen section endings

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/src/bitvec.c b/src/bitvec.c
index 8a086b8..714c11b 100644
--- a/src/bitvec.c
+++ b/src/bitvec.c
@@ -261,4 +261,4 @@
 	return -1;
 }
 
-/*! }@ */
+/*! @} */