[SCSI] megaraid_sas: check return value for megasas_get_pd_list()

When megasas_get_pd_list() fails we cannot detect any drives,
so we should be checking the return value accordingly.

[jejb: checkpatch fix]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -3763,7 +3763,10 @@ static int megasas_init_fw(struct megasas_instance *instance)
 
 	memset(instance->pd_list, 0 ,
 		(MEGASAS_MAX_PD * sizeof(struct megasas_pd_list)));
-	megasas_get_pd_list(instance);
+	if (megasas_get_pd_list(instance) < 0) {
+		printk(KERN_ERR "megasas: failed to get PD list\n");
+		goto fail_init_adapter;
+	}
 
 	memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);
 	if (megasas_ld_list_query(instance,
@@ -5592,7 +5595,7 @@ megasas_aen_polling(struct work_struct *work)
 
 	if (doscan) {
 		printk(KERN_INFO "scanning ...\n");
-		megasas_get_pd_list(instance);
+		if (megasas_get_pd_list(instance) == 0) {
 			for (i = 0; i < MEGASAS_MAX_PD_CHANNELS; i++) {
 				for (j = 0; j < MEGASAS_MAX_DEV_PER_CHANNEL; j++) {
 					pd_index = i*MEGASAS_MAX_DEV_PER_CHANNEL + j;
@@ -5612,6 +5615,7 @@ megasas_aen_polling(struct work_struct *work)
 					}
 				}
 			}
+		}
 
 		if (megasas_ld_list_query(instance,
 					  MR_LD_QUERY_TYPE_EXPOSED_TO_HOST))