early-alieneval: Fix package-related thinko with saved-fp-and-pc logic.

  * Forgot a package prefix for GET-LISP-OBJ-ADDRESS, because the
function symbol was exported from SB!ALIEN-INTERNALS yet defined
in SB!ALIEN, and the prefix wouldn't have been necessary from
SB!ALIEN-INTERNALS.

  * Thanks to Stas Boukarev for the heads-up.