scsi: virtio_scsi: Fix spelling mistake "Unsupport" -> "Unsupported"

There are a couple of spelling mistakes in pr_info and pr_err messages.
Fix them.

Link: https://lore.kernel.org/r/20210924230330.143785-1-colin.king@canonical.com


Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>