Fix travis failure in c7b6b899f1

Looks like my gofmt and the one used by travis do not agree on a comment inside
an empty struct. Move the comment outside the struct to work around the problem.

devices/bmxx80/bmp180_test.go

@@ -16,9 +16,8 @@ var opts180 = &Opts{Temperature: O1x, Pressure: O1x}
 
 func TestNew180_fail_read_chipid(t *testing.T) {
 	bus := i2ctest.Playback{
-		Ops: []i2ctest.IO{
 		// Chip ID detection read fail.
-		},
+		Ops:       []i2ctest.IO{},
 		DontPanic: true,
 	}
 	if _, err := NewI2C(&bus, 0x77, opts180); err == nil {