scsi: target: iscsi: Fix typo in comment

Correct the spelling of Nagle's name in a comment.

Link: https://lore.kernel.org/r/2921.1610694423@turing-police


Reviewed-by: Chaitanya Kulkarni <chiatanya.kulkarni@wdc.com>
Signed-off-by: Valdis Klētnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>