scsi: qla2xxx: Remove unused 'ql_dm_tgt_ex_pct' parameter

The ql_dm_tgt_ex_pct parameter was introduced in commit ead03855
("qla2xxx: Add Dual mode support in the driver"). Then the use of this
parameter was dropped in commit 99e1b683 ("scsi: qla2xxx: Add
ql2xiniexchg parameter").

Thus, remove ql_dm_tgt_ex_pct since it is no longer used.

Link: https://lore.kernel.org/r/AM9PR10MB41185ADE95B92B4E6926BE639DD49@AM9PR10MB4118.EURPRD10.PROD.OUTLOOK.COM


Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Gleb Chesnokov <Chesnokov.G@raidix.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>