scsi: lpfc: Fix use-after-free KFENCE violation during sysfs firmware write

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

scsi: lpfc: Fix use-after-free KFENCE violation during sysfs firmware write

During the sysfs firmware write process, a use-after-free read warning is

logged from the lpfc_wr_object() routine:

BUG: KFENCE: use-after-free read in lpfc_wr_object+0x235/0x310 [lpfc]

Use-after-free read at 0x0000000000cf164d (in kfence-#111):

lpfc_wr_object+0x235/0x310 [lpfc]

lpfc_write_firmware.cold+0x206/0x30d [lpfc]

lpfc_sli4_request_firmware_update+0xa6/0x100 [lpfc]

lpfc_request_firmware_upgrade_store+0x66/0xb0 [lpfc]

kernfs_fop_write_iter+0x121/0x1b0

new_sync_write+0x11c/0x1b0

vfs_write+0x1ef/0x280

ksys_write+0x5f/0xe0

do_syscall_64+0x59/0x90

entry_SYSCALL_64_after_hwframe+0x63/0xcd

The driver accessed wr_object pointer data, which was initialized into

mailbox payload memory, after the mailbox object was released back to the

mailbox pool.

Fix by moving the mailbox free calls to the end of the routine ensuring

that we don't reference internal mailbox memory after release.