IB/cm: Fix missing unlock on error in cm_init_qp_rtr_attr()

Add the missing unlock before return from function cm_init_qp_rtr_attr()
in the error handling case.

Fixes: dd5f03beb4f7 ("IB/core: Ethernet L2 attributes in verbs/cm structures")
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/core/cm.c

@@ -3526,8 +3526,10 @@ static int cm_init_qp_rtr_attr(struct cm_id_private *cm_id_priv,
 		*qp_attr_mask = IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU |
 				IB_QP_DEST_QPN | IB_QP_RQ_PSN;
 		qp_attr->ah_attr = cm_id_priv->av.ah_attr;
-		if (!cm_id_priv->av.valid)
+		if (!cm_id_priv->av.valid) {
+			spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 			return -EINVAL;
+		}
 		if (cm_id_priv->av.ah_attr.vlan_id != 0xffff) {
 			qp_attr->vlan_id = cm_id_priv->av.ah_attr.vlan_id;
 			*qp_attr_mask |= IB_QP_VID;