MEDIUM: connection: no need to recheck FD state

We already have everything in the connection flags using the
CO_FL_DATA_*_ENA bits combined with the fd's ready state, so
we do not need to check fdtab[fd].ev anymore. This considerably
simplifies the connection handling logic since it doesn't
have to mix connection flags with past polling states.
diff --git a/src/connection.c b/src/connection.c
index 876d71a..f85e775 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -92,10 +92,8 @@
 	 * that we must absolutely test conn->xprt at each step in case it suddenly
 	 * changes due to a quick unexpected close().
 	 */
-	if ((fdtab[fd].ev & (FD_POLL_IN | FD_POLL_HUP | FD_POLL_ERR)) &&
-	    conn->xprt &&
-	    fd_recv_ready(fd) &&
-	    !(conn->flags & (CO_FL_WAIT_ROOM|CO_FL_ERROR|CO_FL_HANDSHAKE))) {
+	if (conn->xprt && fd_recv_ready(fd) &&
+	    ((conn->flags & (CO_FL_DATA_RD_ENA|CO_FL_WAIT_ROOM|CO_FL_ERROR|CO_FL_HANDSHAKE)) == CO_FL_DATA_RD_ENA)) {
 		/* force detection of a flag change : it's impossible to have both
 		 * CONNECTED and WAIT_CONN so we're certain to trigger a change.
 		 */
@@ -103,10 +101,8 @@
 		conn->data->recv(conn);
 	}
 
-	if ((fdtab[fd].ev & (FD_POLL_OUT | FD_POLL_ERR)) &&
-	    conn->xprt &&
-	    fd_send_ready(fd) &&
-	    !(conn->flags & (CO_FL_WAIT_DATA|CO_FL_ERROR|CO_FL_HANDSHAKE))) {
+	if (conn->xprt && fd_send_ready(fd) &&
+	    ((conn->flags & (CO_FL_DATA_WR_ENA|CO_FL_WAIT_DATA|CO_FL_ERROR|CO_FL_HANDSHAKE)) == CO_FL_DATA_WR_ENA)) {
 		/* force detection of a flag change : it's impossible to have both
 		 * CONNECTED and WAIT_CONN so we're certain to trigger a change.
 		 */