net/lora/node/src/lora_node.c: crash fix
net/lora/node/src/lora_node.c: crash fix

LoRaMac node crashed on calling a callback whose adress was taken
from the stack and was random, as the structure passed to LoRaMac
was a local variable from the calling function. This sitiuation
occured each time the device processed the DevStatusReq MAC
command.

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core