Bluetooth: Mesh: Fix NULL pointer access with GATT Proxy
Bluetooth: Mesh: Fix NULL pointer access with GATT Proxy

The conversion to the new net_buf_simple API was done incorrectly
here. The buffer initialization should use net_buf_simple_init()
instead of net_buf_simple_reset(), so that buf->__buf gets properly
initialized (and not left pointing at NULL).

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

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