net: lwm2m: firmware_pull: don't use pending pkt for token
net: lwm2m: firmware_pull: don't use pending pkt for token

During firmware transmit timeout, we rely on the pending packet data to
reconstitute the token and token length.  At this point the pending
structure may be cleared out due to multiple retries.  To avoid getting
a zero token, let's use the token data from the original msg structure
instead.

Signed-off-by: Michael Scott <a17fed27eaa842282862ff7c1b9c8395a26ac320@foundries.io>

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