8022532: [parfait] Potential memory leak in gtk2_interface.c

Reviewed-by: art, serb

src/solaris/native/sun/awt/gtk2_interface.c

@@ -794,6 +794,7 @@ gboolean gtk2_load()
             }
             putenv (new_env);
             free (new_env);
+            free (tmp_env);
         }
     }