Bluetooth: Mesh: Friend: Fix setting pending_buf variable
Bluetooth: Mesh: Friend: Fix setting pending_buf variable

The variable for tracking that a buffer from the Friend Queue hasn't
been sent yet was not being properly set.

Signed-off-by: Johan Hedberg <628991c7b0a19c384f9b99c21ec330ce952bb838@intel.com>

kraj/zephyr,zephyriot/zephyr,kraj/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,zephyriot/zephyr,nashif/zephyr,explora26/zephyr,mbolivar/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,ldts/zephyr,Vudentz/zephyr,galak/zephyr,explora26/zephyr,ldts/zephyr,finikorg/zephyr,ldts/zephyr,aceofall/zephyr-iotos,aceofall/zephyr-iotos,Vudentz/zephyr,ldts/zephyr,galak/zephyr,punitvara/zephyr,punitvara/zephyr,zephyriot/zephyr,nashif/zephyr,aceofall/zephyr-iotos,galak/zephyr,explora26/zephyr,zephyriot/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,nashif/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,zephyriot/zephyr,Vudentz/zephyr,punitvara/zephyr,galak/zephyr,explora26/zephyr,finikorg/zephyr,finikorg/zephyr,Vudentz/zephyr,aceofall/zephyr-iotos,Vudentz/zephyr,kraj/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,aceofall/zephyr-iotos,nashif/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,punitvara/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr