scsi: qla4xxx: Remove unneeded if-null-free check

Eliminate the following coccicheck warning:

drivers/scsi/qla4xxx/ql4_os.c:4175:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:4196:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:4215:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:6400:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:6402:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:6555:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:6557:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:7838:2-7: WARNING:
 NULL check before some freeing functions is not needed.
drivers/scsi/qla4xxx/ql4_os.c:7840:2-7: WARNING:
 NULL check before some freeing functions is not needed.

Link: https://lore.kernel.org/r/20210409120345.6447-1-linqiheng@huawei.com


Signed-off-by: Qiheng Lin <linqiheng@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>