log: Fix switch statement
log: Fix switch statement

MISRA-C has several rules about switch statements like each clause
end with an unconditional break. This commit fix these problems to
be in accordance with the standard.

MISRA-C rules 16.1, 16.3 and 16.4

Signed-off-by: Flavio Ceolin <979b9165500b0741b9d0500e2efd74fc1547bff7@intel.com>

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