Bluetooth: Mesh: Fixes pb-adv segment recv
Bluetooth: Mesh: Fixes pb-adv segment recv

Wrong use of function `find_msb_set(~link.rx.seg)`,
uint8_t type is implicitly converted to uint32_t.
As a result, it always returns 32 instead of the
expected value, resulting in abnormal processing
of prov segment.

Signed-off-by: Lingao Meng <d107961e9e4fef34975d9e927886461599dc7eda@xiaomi.com>

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