Fix a mem leak on an error path in OBJ_NAME_add()

If lh_OBJ_NAME_insert() fails then the allocated |onp| value is leaked.

RT#2238
Reviewed-by: NRichard Levitte <levitte@openssl.org>

crypto/objects/o_names.c

@@ -191,7 +191,7 @@ int OBJ_NAME_add(const char *name, int type, const char *data)
     onp = OPENSSL_malloc(sizeof(*onp));
     if (onp == NULL) {
         /* ERROR */
-        return (0);
+        return 0;
     }
 
     onp->name = name;
@@ -216,10 +216,11 @@ int OBJ_NAME_add(const char *name, int type, const char *data)
     } else {
         if (lh_OBJ_NAME_error(names_lh)) {
             /* ERROR */
-            return (0);
+            OPENSSL_free(onp);
+            return 0;
         }
     }
-    return (1);
+    return 1;
 }
 
 int OBJ_NAME_remove(const char *name, int type)