ztest: remove unused include of sys_log.h
ztest: remove unused include of sys_log.h

Remove include that is not being used in the file.

Signed-off-by: Anas Nashif <0d9952ec84ac43c159f6b7e7ed99a9080c00dd6e@intel.com>

ldts/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,galak/zephyr,Vudentz/zephyr,finikorg/zephyr,explora26/zephyr,punitvara/zephyr,Vudentz/zephyr,punitvara/zephyr,nashif/zephyr,nashif/zephyr,punitvara/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,Vudentz/zephyr,nashif/zephyr,nashif/zephyr,explora26/zephyr,Vudentz/zephyr,galak/zephyr,galak/zephyr