test: fix typo

R=ken2
CC=golang-dev
https://golang.org/cl/5752073

test/fixedbugs/bug424.go

@@ -5,7 +5,7 @@
 // license that can be found in the LICENSE file.
 
 // Tests that method calls through an interface always
-// call the the locally defined method localT.m independent
+// call the locally defined method localT.m independent
 // at which embedding level it is and in which order
 // embedding is done.