ice: Fix NULL pointer dereference in ice_vsi_set_napi_queues

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

ice: Fix NULL pointer dereference in ice_vsi_set_napi_queues

Add NULL pointer checks in ice_vsi_set_napi_queues() to prevent crashes
during resume from suspend when rings[q_idx]->q_vector is NULL.

Tested adaptor:
60:00.0 Ethernet controller [0200]: Intel Corporation Ethernet Controller E810-XXV for SFP [8086:159b] (rev 02)
Subsystem: Intel Corporation Ethernet Network Adapter E810-XXV-2 [8086:4003]

SR-IOV state: both disabled and enabled can reproduce this issue.

kernel version: v6.18

Reproduce steps:
Boot up and execute suspend like systemctl suspend or rtcwake.

Log:
<1>[ 231.443607] BUG: kernel NULL pointer dereference, address: 0000000000000040
<1>[ 231.444052] #PF: supervisor read access in kernel mode
<1>[ 231.444484] #PF: error_code(0x0000) - not-present page
<6>[ 231.444913] PGD 0 P4D 0
<4>[ 231.445342] Oops: Oops: 0000 [#1] SMP NOPTI
<4>[ 231.446635] RIP: 0010:netif_queue_set_napi+0xa/0x170
<4>[ 231.447067] Code: 31 f6 31 ff c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48 85 c9 74 0b <48> 83 79 30 00 0f 84 39 01 00 00 55 41 89 d1 49 89 f8 89 f2 48 89
<4>[ 231.447513] RSP: 0018:ffffcc780fc078c0 EFLAGS: 00010202
<4>[ 231.447961] RAX: ffff8b848ca30400 RBX: ffff8b848caf2028 RCX: 0000000000000010
<4>[ 231.448443] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8b848dbd4000
<4>[ 231.448896] RBP: ffffcc780fc078e8 R08: 0000000000000000 R09: 0000000000000000
<4>[ 231.449345] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
<4>[ 231.449817] R13: ffff8b848dbd4000 R14: ffff8b84833390c8 R15: 0000000000000000
<4>[ 231.450265] FS: 00007c7b29e9d740(0000) GS:ffff8b8c068e2000(0000) knlGS:0000000000000000
<4>[ 231.450715] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[ 231.451179] CR2: 0000000000000040 CR3: 000000030626f004 CR4: 0000000000f72ef0
<4>[ 231.451629] PKRU: 55555554
<4>[ 231.452076] Call Trace:
<4>[ 231.452549] <TASK>
<4>[ 231.452996] ? ice_vsi_set_napi_queues+0x4d/0x110 [ice]
<4>[ 231.453482] ice_resume+0xfd/0x220 [ice]
<4>[ 231.453977] ? __pfx_pci_pm_resume+0x10/0x10
<4>[ 231.454425] pci_pm_resume+0x8c/0x140
<4>[ 231.454872] ? __pfx_pci_pm_resume+0x10/0x10
<4>[ 231.455347] dpm_run_callback+0x5f/0x160
<4>[ 231.455796] ? dpm_wait_for_superior+0x107/0x170
<4>[ 231.456244] device_resume+0x177/0x270
<4>[ 231.456708] dpm_resume+0x209/0x2f0
<4>[ 231.457151] dpm_resume_end+0x15/0x30
<4>[ 231.457596] suspend_devices_and_enter+0x1da/0x2b0
<4>[ 231.458054] enter_state+0x10e/0x570

Add defensive checks for both the ring pointer and its q_vector
before dereferencing, allowing the system to resume successfully even when
q_vectors are unmapped.