device property: Avoid NULL pointer dereference in device_get_next_child_node()

device property: Avoid NULL pointer dereference in device_get_next_child_node()

When we have no primary fwnode or when it's a software node, we may end up
in the situation when fwnode is a NULL pointer. There is no point to look for
secondary fwnode in such case. Add a necessary check to a condition.

Fixes: 114dbb4fa7c4 ("drivers property: When no children in primary, try secondary")
Reported-by: Maxim Levitsky <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Tested-by: Maxim Levitsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>