ice: fix eswitch code memory leak in reset scenario

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

ice: fix eswitch code memory leak in reset scenario

Add simple eswitch mode checker in attaching VF procedure and allocate

required port representor memory structures only in switchdev mode.

The reset flows triggers VF (if present) detach/attach procedure.

It might involve VF port representor(s) re-creation if the device is

configured is switchdev mode (not legacy one).

The memory was blindly allocated in current implementation,

regardless of the mode and not freed if in legacy mode.

Kmemeleak trace:

unreferenced object (percpu) 0x7e3bce5b888458 (size 40):

comm "bash", pid 1784, jiffies 4295743894

hex dump (first 32 bytes on cpu 45):

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

backtrace (crc 0):

pcpu_alloc_noprof+0x4c4/0x7c0

ice_repr_create+0x66/0x130 [ice]

ice_repr_create_vf+0x22/0x70 [ice]

ice_eswitch_attach_vf+0x1b/0xa0 [ice]

ice_reset_all_vfs+0x1dd/0x2f0 [ice]

ice_pci_err_resume+0x3b/0xb0 [ice]

pci_reset_function+0x8f/0x120

reset_store+0x56/0xa0

kernfs_fop_write_iter+0x120/0x1b0

vfs_write+0x31c/0x430

ksys_write+0x61/0xd0

do_syscall_64+0x5b/0x180

entry_SYSCALL_64_after_hwframe+0x76/0x7e

Testing hints (ethX is PF netdev):

- create at least one VF

echo 1 > /sys/class/net/ethX/device/sriov_numvfs

- trigger the reset

echo 1 > /sys/class/net/ethX/device/reset