[SCSI] qla2xxx: Properly set the dsd_list_len for dsd_chaining in cmd type 6.

The firmware spec has the fcp_data_dseg_len defined as a 32-bit
value, while the corresponding field in the driver structure has
it defined as a 16-bit value.

Cc: stable@kernel.org
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Madhuranath Iyengar <Madhu.Iyengar@qlogic.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <jbottomley@parallels.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>