target/stm8: add missing destroy_reg_param()

Change-Id: Ibd8a423a4400226790cfbb9a6f113b7ea762c436
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4814
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Ake Rehnman <ake.rehnman@gmail.com>

src/target/stm8.c

@@ -1805,6 +1805,7 @@ static int stm8_blank_check_memory(struct target *target,
 	destroy_mem_param(&mem_params[0]);
 	destroy_mem_param(&mem_params[1]);
 	destroy_reg_param(&reg_params[0]);
+	destroy_reg_param(&reg_params[1]);
 
 	target_free_working_area(target, erase_check_algorithm);