scsi: pm80xx: Fix pm8001_mpi_get_nvmd_resp() race condition

scsi: pm80xx: Fix pm8001_mpi_get_nvmd_resp() race condition

A use-after-free or null-pointer error occurs when the 251-byte response
data is copied from IOMB buffer to response message buffer in function
pm8001_mpi_get_nvmd_resp().

After sending the command get_nvmd_data(), the caller begins to sleep by
calling wait_for_complete() and waits for the wake-up from calling
complete() in pm8001_mpi_get_nvmd_resp(). Due to unexpected events (e.g.,
interrupt), if response buffer gets freed before memcpy(), a use-after-free
error will occur. To fix this, the complete() should be called after
memcpy().

Link: https://lore.kernel.org/r/20201102165528.26510-5-Viswas.G@microchip.com.com
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: yuuzheng <yuuzheng@google.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Radha Ramachandran <radha@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>