scsi: core: Call scsi_done directly

scsi: core: Call scsi_done directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly. Since this patch removes the last user of the
scsi_done member, also remove that data structure member.

Link: https://lore.kernel.org/r/20211007204618.2196847-11-bvanassche@acm.org
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>