options/m_option: free all list elements when removing them

Elements are not parented to the add list, as they are directly copied
to the target list. Therefore, we need to clean them up manually.

Fixes: 1f5a67d8fa

options/m_option.c

@@ -1319,6 +1319,8 @@ static int str_list_add(char **add, int n, void *dst, int pre)
 
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
     if (ln >= 100) {
+        while (n--)
+            talloc_free(add[n]);
         talloc_free(add);
         return 0;
     }