cmd/gofmt: remove testdata/*.gofmt files

This files were added accidentally and are
not required for running the tests (they
are produced by failing tests for easier
debugging).

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/131030044

src/cmd/gofmt/testdata/stdin1.golden.gofmt

-	if x {
-	y
-}

src/cmd/gofmt/testdata/stdin1.input.gofmt

-	if x {
-	y
-}

src/cmd/gofmt/testdata/stdin2.golden.gofmt

-
-
-
-var x int
-
-func f() {
-	y := z
-}
-
-

src/cmd/gofmt/testdata/stdin2.input.gofmt

-
-
-var x int
-
-func f() {
-	y := z
-	/* this is a comment */
-	// this is a comment too
-}
-
-

src/cmd/gofmt/testdata/stdin3.golden.gofmt

-
-
-		/* note: no newline at end of file */
-		for i := 0; i < 10; i++ {
-			s += i
-		}
-	
\ No newline at end of file

src/cmd/gofmt/testdata/stdin3.input.gofmt

-
-
-		/* note: no newline at end of file */
-		for i := 0; i < 10; i++ {
-			s += i
-		}
-	
\ No newline at end of file

src/cmd/gofmt/testdata/stdin4.golden.gofmt

-	// comment
-
-	i := 0

src/cmd/gofmt/testdata/stdin4.input.gofmt

-	// comment
-
-	i := 0