hst/fs: remove type method

Having a method that returns the canonical string representation of its type seemed like a much better idea for an implementation that never made it to staging. Remove it here and clean up marshal type assertions.

Signed-off-by: Ophestra <cat@gensokyo.uk>

hst/fsbind_test.go

@@ -8,7 +8,7 @@ import (
 )
 
 func TestFSBind(t *testing.T) {
-	checkFs(t, "bind", []fsTestCase{
+	checkFs(t, []fsTestCase{
 		{"nil", (*hst.FSBind)(nil), false, nil, nil, nil, "<invalid>"},
 
 		{"full", &hst.FSBind{