scsi: target/core: Use kvcalloc() instead of open-coding it

This patch does not change any functionality. Note: the code that frees
sess_cmd_map already uses kvfree() so that code does not need to be
modified.
Reviewed-by: NDavid Disseldorp <ddiss@suse.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/target/target_core_transport.c

@@ -273,14 +273,11 @@ int transport_alloc_session_tags(struct se_session *se_sess,
 {
 	int rc;
 
-	se_sess->sess_cmd_map = kcalloc(tag_size, tag_num,
-					GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
+	se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
+					 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 	if (!se_sess->sess_cmd_map) {
-		se_sess->sess_cmd_map = vzalloc(array_size(tag_size, tag_num));
-		if (!se_sess->sess_cmd_map) {
-			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
-			return -ENOMEM;
-		}
+		pr_err("Unable to allocate se_sess->sess_cmd_map\n");
+		return -ENOMEM;
 	}
 
 	rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,