scsi: qla2xxx: Remove unneeded if-null-free check

scsi: qla2xxx: Remove unneeded if-null-free check

Eliminate the following coccicheck warning:

drivers/scsi/qla2xxx/qla_os.c:4622:2-7:
 WARNING: NULL check before some freeing functions is not needed.
drivers/scsi/qla2xxx/qla_os.c:4637:3-8:
 WARNING: NULL check before some freeing functions is not needed.

Link: https://lore.kernel.org/r/20210409120925.7122-1-linqiheng@huawei.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Qiheng Lin <linqiheng@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>