Red Hat: CVE-2021-47503: kernel: scsi: pm80xx: Do not call scsi_remove_host() in pm8001_alloc()

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

scsi: pm80xx: Do not call scsi_remove_host() in pm8001_alloc()

Calling scsi_remove_host() before scsi_add_host() results in a crash:

BUG: kernel NULL pointer dereference, address: 0000000000000108
RIP: 0010:device_del+0x63/0x440
Call Trace:
device_unregister+0x17/0x60
scsi_remove_host+0xee/0x2a0
pm8001_pci_probe+0x6ef/0x1b90 [pm80xx]
local_pci_probe+0x3f/0x90

We cannot call scsi_remove_host() in pm8001_alloc() because scsi_add_host()
has not been called yet at that point in time.

Function call tree:

pm8001_pci_probe()
|
`- pm8001_pci_alloc()
| |
| `- pm8001_alloc()
| |
| `- scsi_remove_host()
|
`- scsi_add_host()