goinstall: fix documentation typo

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/2585043

src/cmd/goinstall/doc.go

diff --git a/src/cmd/goinstall/doc.go b/src/cmd/goinstall/doc.go
index 5705266..17cc069 100644
--- a/src/cmd/goinstall/doc.go
+++ b/src/cmd/goinstall/doc.go
@@ -50,8 +50,8 @@
 
 	GitHub (Git)
 
-		import "github.com/user/project.git"
-		import "github.com/user/project.git/sub/directory"
+		import "github.com/user/project"
+		import "github.com/user/project/sub/directory"
 
 	Google Code Project Hosting (Mercurial, Subversion)