[SCSI] iscsi: fix crypto_alloc_hash() error check

The return value of crypto_alloc_hash() should be checked by
IS_ERR().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/iscsi_tcp.c

@@ -1777,13 +1777,13 @@ iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
 	tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 						  CRYPTO_ALG_ASYNC);
 	tcp_conn->tx_hash.flags = 0;
-	if (!tcp_conn->tx_hash.tfm)
+	if (IS_ERR(tcp_conn->tx_hash.tfm))
 		goto free_tcp_conn;
 
 	tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 						  CRYPTO_ALG_ASYNC);
 	tcp_conn->rx_hash.flags = 0;
-	if (!tcp_conn->rx_hash.tfm)
+	if (IS_ERR(tcp_conn->rx_hash.tfm))
 		goto free_tx_tfm;
 
 	return cls_conn;