Add configure script

Get rid of all the fragile guessing and checking of features,
and roll a configure script instead.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/engines/net.c b/engines/net.c
index edb5577..eb05bcc 100644
--- a/engines/net.c
+++ b/engines/net.c
@@ -157,7 +157,7 @@
 	return 0;
 }
 
-#ifdef FIO_HAVE_SPLICE
+#ifdef CONFIG_LINUX_SPLICE
 static int splice_io_u(int fdin, int fdout, unsigned int len)
 {
 	int bytes = 0;
@@ -352,7 +352,7 @@
 
 	do {
 		if (o->proto == FIO_TYPE_UDP) {
-			fio_socklen_t len = sizeof(nd->addr);
+			socklen_t len = sizeof(nd->addr);
 			struct sockaddr *from = (struct sockaddr *) &nd->addr;
 
 			ret = recvfrom(io_u->file->fd, io_u->xfer_buf,
@@ -474,7 +474,7 @@
 	if (o->proto == FIO_TYPE_UDP)
 		return 0;
 	else if (o->proto == FIO_TYPE_TCP) {
-		fio_socklen_t len = sizeof(nd->addr);
+		socklen_t len = sizeof(nd->addr);
 
 		if (connect(f->fd, (struct sockaddr *) &nd->addr, len) < 0) {
 			td_verror(td, errno, "connect");
@@ -483,7 +483,7 @@
 		}
 	} else {
 		struct sockaddr_un *addr = &nd->addr_un;
-		fio_socklen_t len;
+		socklen_t len;
 
 		len = sizeof(addr->sun_family) + strlen(addr->sun_path) + 1;
 
@@ -501,7 +501,7 @@
 {
 	struct netio_data *nd = td->io_ops->data;
 	struct netio_options *o = td->eo;
-	fio_socklen_t socklen = sizeof(nd->addr);
+	socklen_t socklen = sizeof(nd->addr);
 	int state;
 
 	if (o->proto == FIO_TYPE_UDP) {
@@ -566,7 +566,7 @@
 	struct netio_data *nd = td->io_ops->data;
 	struct udp_close_msg msg;
 	struct sockaddr *to = (struct sockaddr *) &nd->addr;
-	fio_socklen_t len = sizeof(nd->addr);
+	socklen_t len = sizeof(nd->addr);
 	int ret;
 
 	ret = recvfrom(f->fd, &msg, sizeof(msg), MSG_WAITALL, to, &len);
@@ -887,7 +887,7 @@
 	kill(td->pid, SIGUSR2);
 }
 
-#ifdef FIO_HAVE_SPLICE
+#ifdef CONFIG_LINUX_SPLICE
 static int fio_netio_setup_splice(struct thread_data *td)
 {
 	struct netio_data *nd;
@@ -954,7 +954,7 @@
 static void fio_init fio_netio_register(void)
 {
 	register_ioengine(&ioengine_rw);
-#ifdef FIO_HAVE_SPLICE
+#ifdef CONFIG_LINUX_SPLICE
 	register_ioengine(&ioengine_splice);
 #endif
 }
@@ -962,7 +962,7 @@
 static void fio_exit fio_netio_unregister(void)
 {
 	unregister_ioengine(&ioengine_rw);
-#ifdef FIO_HAVE_SPLICE
+#ifdef CONFIG_LINUX_SPLICE
 	unregister_ioengine(&ioengine_splice);
 #endif
 }