scsi: core: Simplify scsi_cdl_check_cmd()

Reading the 800+ pages of SPC often leads to a brain shutdown and to less
than ideal code... This resulted in the checks of the rwcdlp and cdlp
fields in scsi_cdl_check_cmd() to have identical if-else branches.

Replace this with a comment describing the cases we are interested in and
replace the if-else code block with a simple test of the cdlp field that is
used as the function return value.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/r/202306221657.BJHEADkz-lkp@intel.com/


Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230623073057.816199-1-dlemoal@kernel.org


Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>