scsi: mvumi: Update function description

There is no "device" parameter in mvumi_shutdown(). Instead there is "pdev"
which is not described.

Link: https://lore.kernel.org/r/20201102164730.324035-28-vaibhavgupta40@gmail.com


Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>