svcrdma: Provide an explanatory comment in CMA event handler

Clean up: explain why svc_xprt_enqueue() is invoked in the event
handler even though no xpt_flags bits are toggled here.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

net/sunrpc/xprtrdma/svc_rdma_transport.c

@@ -279,6 +279,9 @@ static int svc_rdma_cma_handler(struct rdma_cm_id *cma_id,
 	switch (event->event) {
 	case RDMA_CM_EVENT_ESTABLISHED:
 		clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags);
+
+		/* Handle any requests that were received while
+		 * CONN_PENDING was set. */
 		svc_xprt_enqueue(xprt);
 		break;
 	case RDMA_CM_EVENT_DISCONNECTED: