scsi: core: Fix spelling in a source code comment

The typo in this source code comment makes the comment confusing. Clear up
the confusion by fixing the typo.

Link: https://lore.kernel.org/r/20210929182318.2060489-1-bvanassche@acm.org
Fixes: bc85dc50

 ("scsi: remove scsi_end_request")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>