io_uring/zcrx: fix null ifq on area destruction

io_uring/zcrx: fix null ifq on area destruction

Dan reports that ifq can be null when infering arguments for
io_unaccount_mem() from io_zcrx_free_area(). Fix it by always setting a
correct ifq.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202507180628.gBxrOgqr-lkp@intel.com/
Fixes: 262ab205180d2 ("io_uring/zcrx: account area memory")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20670d163bb90dba2a81a4150f1125603cefb101.1753091564.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>