scsi: aic94xx: Remove unnecessary null check

kmem_cache_destroy() can handle NULL pointer correctly, so there is no need
to check NULL pointer before calling kmem_cache_destroy().

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/aic94xx/aic94xx_init.c

@@ -565,7 +565,6 @@ static void asd_destroy_ha_caches(struct asd_ha_struct *asd_ha)
 	if (asd_ha->hw_prof.scb_ext)
 		asd_free_coherent(asd_ha, asd_ha->hw_prof.scb_ext);
 
-	if (asd_ha->hw_prof.ddb_bitmap)
 	kfree(asd_ha->hw_prof.ddb_bitmap);
 	asd_ha->hw_prof.ddb_bitmap = NULL;
 
@@ -641,11 +640,9 @@ Err:
 
 static void asd_destroy_global_caches(void)
 {
-	if (asd_dma_token_cache)
 	kmem_cache_destroy(asd_dma_token_cache);
 	asd_dma_token_cache = NULL;
 
-	if (asd_ascb_cache)
 	kmem_cache_destroy(asd_ascb_cache);
 	asd_ascb_cache = NULL;
 }