net: marvell: prestera: fix double free issue on err path

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

net: marvell: prestera: fix double free issue on err path

fix error path handling in prestera_bridge_port_join() that

cases prestera driver to crash (see below).

Trace:

Internal error: Oops: 96000044 [#1] SMP

Modules linked in: prestera_pci prestera uio_pdrv_genirq

CPU: 1 PID: 881 Comm: ip Not tainted 5.15.0 #1

pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)

pc : prestera_bridge_destroy+0x2c/0xb0 [prestera]

lr : prestera_bridge_port_join+0x2cc/0x350 [prestera]

sp : ffff800011a1b0f0

...

x2 : ffff000109ca6c80 x1 : dead000000000100 x0 : dead000000000122

Call trace:

prestera_bridge_destroy+0x2c/0xb0 [prestera]

prestera_bridge_port_join+0x2cc/0x350 [prestera]

prestera_netdev_port_event.constprop.0+0x3c4/0x450 [prestera]

prestera_netdev_event_handler+0xf4/0x110 [prestera]

raw_notifier_call_chain+0x54/0x80

call_netdevice_notifiers_info+0x54/0xa0

__netdev_upper_dev_link+0x19c/0x380