kernel/idle.c: fix compilation failure (SMP && !SCHED_IPI_SUPPORTED)
kernel/idle.c: fix compilation failure (SMP && !SCHED_IPI_SUPPORTED)

An #endif and the brace terminating a compound statement were
transposed, causing compilation errors with the above-specified
combination of configuration options.

Signed-off-by: Charles E. Youse <5bc2c6f24e92b68873229a004438f1d6a77a3862@intel.com>

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