twister: fix the inconsistent total tests number
twister: fix the inconsistent total tests number

sometimes a test instance hasn't been boot up to execute successfully,
so the results is an empty dictionary, it will not be added into final
twister_report.xml file.
in order to include it, fill the results as BLOCK.

Signed-off-by: peng1 chen <a9104ed43ee1e05962395401b47b879b137cfacf@intel.com>

Vudentz/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,galak/zephyr,Vudentz/zephyr,finikorg/zephyr,finikorg/zephyr,nashif/zephyr,finikorg/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr,Vudentz/zephyr