tun: remove TUN prefix from types to reduce stutter elsewhere

Signed-off-by: Matt Layher <mdlayher@gmail.com>

tun/tun.go

@@ -9,21 +9,21 @@ import (
 	"os"
 )
 
-type TUNEvent int
+type Event int
 
 const (
-	TUNEventUp = 1 << iota
-	TUNEventDown
-	TUNEventMTUUpdate
+	EventUp = 1 << iota
+	EventDown
+	EventMTUUpdate
 )
 
-type TUNDevice interface {
+type Device interface {
 	File() *os.File                 // returns the file descriptor of the device
 	Read([]byte, int) (int, error)  // read a packet from the device (without any additional headers)
 	Write([]byte, int) (int, error) // writes a packet to the device (without any additional headers)
 	Flush() error                   // flush all previous writes to the device
 	MTU() (int, error)              // returns the MTU of the device
 	Name() (string, error)          // fetches and returns the current name
-	Events() chan TUNEvent          // returns a constant channel of events related to the device
+	Events() chan Event             // returns a constant channel of events related to the device
 	Close() error                   // stops the device and closes the event channel
 }