mt76: mt7921: fix kernel crash when the firmware fails to download

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

mt76: mt7921: fix kernel crash when the firmware fails to download

Fix kernel crash when the firmware is missing or fails to download.

[ 9.444758] kernel BUG at drivers/pci/msi.c:375!

[ 9.449363] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP

[ 9.501033] pstate: a0400009 (NzCv daif +PAN -UAO)

[ 9.505814] pc : free_msi_irqs+0x180/0x184

[ 9.509897] lr : free_msi_irqs+0x40/0x184

[ 9.513893] sp : ffffffc015193870

[ 9.517194] x29: ffffffc015193870 x28: 00000000f0e94fa2

[ 9.522492] x27: 0000000000000acd x26: 000000000000009a

[ 9.527790] x25: ffffffc0152cee58 x24: ffffffdbb383e0d8

[ 9.533087] x23: ffffffdbb38628d0 x22: 0000000000040200

[ 9.538384] x21: ffffff8cf7de7318 x20: ffffff8cd65a2480

[ 9.543681] x19: ffffff8cf7de7000 x18: 0000000000000000

[ 9.548979] x17: ffffff8cf9ca03b4 x16: ffffffdc13ad9a34

[ 9.554277] x15: 0000000000000000 x14: 0000000000080800

[ 9.559575] x13: ffffff8cd65a2980 x12: 0000000000000000

[ 9.564873] x11: ffffff8cfa45d820 x10: ffffff8cfa45d6d0

[ 9.570171] x9 : 0000000000000040 x8 : ffffff8ccef1b780

[ 9.575469] x7 : aaaaaaaaaaaaaaaa x6 : 0000000000000000

[ 9.580766] x5 : ffffffdc13824900 x4 : ffffff8ccefe0000

[ 9.586063] x3 : 0000000000000000 x2 : 0000000000000000

[ 9.591362] x1 : 0000000000000125 x0 : ffffff8ccefe0000

[ 9.596660] Call trace:

[ 9.599095] free_msi_irqs+0x180/0x184

[ 9.602831] pci_disable_msi+0x100/0x130

[ 9.606740] pci_free_irq_vectors+0x24/0x30

[ 9.610915] mt7921_pci_probe+0xbc/0x250 [mt7921e]

[ 9.615693] pci_device_probe+0xd4/0x14c

[ 9.619604] really_probe+0x134/0x2ec

[ 9.623252] driver_probe_device+0x64/0xfc

[ 9.627335] device_driver_attach+0x4c/0x6c

[ 9.631506] __driver_attach+0xac/0xc0

[ 9.635243] bus_for_each_dev+0x8c/0xd4

[ 9.639066] driver_attach+0x2c/0x38

[ 9.642628] bus_add_driver+0xfc/0x1d0

[ 9.646365] driver_register+0x64/0xf8

[ 9.650101] __pci_register_driver+0x6c/0x7c

[ 9.654360] init_module+0x28/0xfdc [mt7921e]

[ 9.658704] do_one_initcall+0x13c/0x2d0

[ 9.662615] do_init_module+0x58/0x1e8

[ 9.666351] load_module+0xd80/0xeb4

[ 9.669912] __arm64_sys_finit_module+0xa8/0xe0

[ 9.674430] el0_svc_common+0xa4/0x16c

[ 9.678168] el0_svc_compat_handler+0x2c/0x40

[ 9.682511] el0_svc_compat+0x8/0x10

[ 9.686076] Code: a94257f6 f9400bf7 a8c47bfd d65f03c0 (d4210000)

[ 9.692155] ---[ end trace 7621f966afbf0a29 ]---

[ 9.697385] Kernel panic - not syncing: Fatal exception

[ 9.702599] SMP: stopping secondary CPUs

[ 9.706549] Kernel Offset: 0x1c03600000 from 0xffffffc010000000

[ 9.712456] PHYS_OFFSET: 0xfffffff440000000

[ 9.716625] CPU features: 0x080026,2a80aa18

[ 9.720795] Memory Limit: none