Fixes the following W=1 kernel build warning(s):

 drivers/scsi/qla4xxx/ql4_os.c: In function ‘qla4xxx_eh_cmd_timed_out’:
 drivers/scsi/qla4xxx/ql4_os.c:1865:24: warning: variable ‘sess’ set but not used [-Wunused-but-set-variable]
 1865 | struct iscsi_session *sess;
 | ^~~~
 drivers/scsi/qla4xxx/ql4_os.c: In function ‘qla4xxx_session_create’:
 drivers/scsi/qla4xxx/ql4_os.c:3079:19: warning: variable ‘dst_addr’ set but not used [-Wunused-but-set-variable]
 3079 | struct sockaddr *dst_addr;
 | ^~~~~~~~
 drivers/scsi/qla4xxx/ql4_os.c: In function ‘qla4_8xxx_iospace_config’:
 drivers/scsi/qla4xxx/ql4_os.c:5512:44: warning: variable ‘db_len’ set but not used [-Wunused-but-set-variable]
 5512 | unsigned long mem_base, mem_len, db_base, db_len;
 | ^~~~~~
 drivers/scsi/qla4xxx/ql4_os.c:5512:35: warning: variable ‘db_base’ set but not used [-Wunused-but-set-variable]
 5512 | unsigned long mem_base, mem_len, db_base, db_len;
 | ^~~~~~~
 drivers/scsi/qla4xxx/ql4_os.c: In function ‘qla4xxx_get_param_ddb’:
 drivers/scsi/qla4xxx/ql4_os.c:6269:24: warning: variable ‘ha’ set but not used [-Wunused-but-set-variable]
 6269 | struct scsi_qla_host *ha;
 | ^~

Link: https://lore.kernel.org/r/20200721164148.2617584-19-lee.jones@linaro.org
Cc: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>