net: remove comment fragments

I have no idea how I meant to complete that sentence.

R=r, r2
CC=golang-dev
https://golang.org/cl/4191046

src/pkg/net/net.go

@@ -31,7 +31,6 @@ type Conn interface {
 	Write(b []byte) (n int, err os.Error)
 
 	// Close closes the connection.
-	// The error returned is an os.Error to satisfy io.Closer;
 	Close() os.Error
 
 	// LocalAddr returns the local network address.
@@ -83,7 +82,6 @@ type PacketConn interface {
 	WriteTo(b []byte, addr Addr) (n int, err os.Error)
 
 	// Close closes the connection.
-	// The error returned is an os.Error to satisfy io.Closer;
 	Close() os.Error
 
 	// LocalAddr returns the local network address.
@@ -112,7 +110,6 @@ type Listener interface {
 	Accept() (c Conn, err os.Error)
 
 	// Close closes the listener.
-	// The error returned is an os.Error to satisfy io.Closer;
 	Close() os.Error
 
 	// Addr returns the listener's network address.