netdev: Get rid of netdev_open_tap().

netdev_open() can always be used in place of netdev_open_tap().  The
former is going to be generalized to support pluggable network device
types, so it makes sense to use it everywhere.

lib/dpif-netdev.c

@@ -377,7 +377,9 @@ do_add_port(struct dp_netdev *dp, const char *devname, uint16_t flags,
     if (!internal) {
         error = netdev_open(devname, NETDEV_ETH_TYPE_ANY, &netdev);
     } else {
-        error = netdev_open_tap(devname, &netdev);
+        char *tapname = xasprintf("tap:%s", devname);
+        error = netdev_open(tapname, NETDEV_ETH_TYPE_ANY, &netdev);
+        free(tapname);
     }
     if (error) {
         return error;

lib/netdev.c

@@ -335,21 +335,9 @@ do_get_features(struct netdev *netdev,
 int
 netdev_open(const char *name, int ethertype, struct netdev **netdevp) 
 {
-    if (!strncmp(name, "tap:", 4)) {
-        return netdev_open_tap(name + 4, netdevp);
-    } else {
+    if (strncmp(name, "tap:", 4)) {
         return do_open_netdev(name, ethertype, -1, netdevp); 
-    }
-}
-
-/* Opens a TAP virtual network device.  If 'name' is a nonnull, non-empty
- * string, attempts to assign that name to the TAP device (failing if the name
- * is already in use); otherwise, a name is automatically assigned.  Returns
- * zero if successful, otherwise a positive errno value.  On success, sets
- * '*netdevp' to the new network device, otherwise to null.  */
-int
-netdev_open_tap(const char *name, struct netdev **netdevp)
-{
+    } else {
         static const char tap_dev[] = "/dev/net/tun";
         struct ifreq ifr;
         int error;
@@ -387,6 +375,8 @@ netdev_open_tap(const char *name, struct netdev **netdevp)
         }
         return error;
     }
+}
+
 
 static int
 do_open_netdev(const char *name, int ethertype, int tap_fd,

lib/netdev.h

@@ -75,7 +75,6 @@ struct netdev_stats {
 struct netdev;
 
 int netdev_open(const char *name, int ethertype, struct netdev **);
-int netdev_open_tap(const char *name, struct netdev **);
 void netdev_close(struct netdev *);
 
 int netdev_recv(struct netdev *, struct ofpbuf *);