types: don't compute effective masks here as well

types: don't compute effective masks here as well

After compiling all of the sections, UpdateModifiersFromCompat does all
of the vmod -> real mods translations, including types/kt_entries.

keytypes.c also has code that does that, but it's unneeded:
- Later sections don't look at their effective masks, so doing it later
  is fine.
- When this code is executed, the vmods -> real mods mapping is empty
  (that is set up later), so VModsToReal has no effect here.
So we can just remove it.

However UpdateModifiersFromCompat didn't update the preserve mask, so do
that.

Signed-off-by: Ran Benita <ran234@gmail.com>