nfc: pn533: initialize struct pn533_out_arg properly

In the Linux kernel, the following vulnerability has been resolved:

nfc: pn533: initialize struct pn533_out_arg properly

struct pn533_out_arg used as a temporary context for out_urb is not
initialized properly. Its uninitialized 'phy' field can be dereferenced in
error cases inside pn533_out_complete() callback function. It causes the
following failure:

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc3-next-20230110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:pn533_out_complete.cold+0x15/0x44 drivers/nfc/pn533/usb.c:441
Call Trace:
<IRQ>
__usb_hcd_giveback_urb+0x2b6/0x5c0 drivers/usb/core/hcd.c:1671
usb_hcd_giveback_urb+0x384/0x430 drivers/usb/core/hcd.c:1754
dummy_timer+0x1203/0x32d0 drivers/usb/gadget/udc/dummy_hcd.c:1988
call_timer_fn+0x1da/0x800 kernel/time/timer.c:1700
expire_timers+0x234/0x330 kernel/time/timer.c:1751
__run_timers kernel/time/timer.c:2022 [inline]
__run_timers kernel/time/timer.c:1995 [inline]
run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035
__do_softirq+0x1fb/0xaf6 kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107

Initialize the field with the pn533_usb_phy currently used.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.