doc: Fix the Doxygen section endings

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/core/select.h b/include/osmocom/core/select.h
index 18aad35..efdd716 100644
--- a/include/osmocom/core/select.h
+++ b/include/osmocom/core/select.h
@@ -40,6 +40,6 @@
 void osmo_fd_unregister(struct osmo_fd *fd);
 int osmo_select_main(int polling);
 
-/*! }@ */
+/*! @} */
 
 #endif /* _BSC_SELECT_H */