lib/godoc: use Type.Name directly
lib/godoc: use Type.Name directly

Also: remove an unused template variable declaration.

R=adg
CC=golang-dev
http://codereview.appspot.com/5572043

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang