firewire: net: fix unexpected release of object for asynchronous request packet

The lifetime of object for asynchronous request packet is now maintained
by reference counting, while current implementation of firewire-net
releases the passed object in the handler.

This commit fixes the bug.

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/lkml/Y%2Fymx6WZIAlrtjLc@workstation/
Fixes: 13a55d6b ("firewire: core: use kref structure to maintain lifetime of data for fw_request structure")
Link: https://lore.kernel.org/lkml/20230510031205.782032-1-o-takashi@sakamocchi.jp/


Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>