scsi: qedf: Add missing return in qedf_scsi_done()

On completions where we do not have a bad scsi_cmnd pointer we should
return before the the label lest we do a double kref_put.

Signed-off-by: Chad Dupuis <cdupuis@marvell.com>
Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>