doc: Fix the Doxygen section endings

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/core/logging.h b/include/osmocom/core/logging.h
index 043a850..76be100 100644
--- a/include/osmocom/core/logging.h
+++ b/include/osmocom/core/logging.h
@@ -206,6 +206,6 @@
 struct log_target *log_target_find(int type, const char *fname);
 extern struct llist_head osmo_log_target_list;
 
-/*! }@ */
+/*! @} */
 
 #endif /* _OSMOCORE_LOGGING_H */