ASLTS: Fix for region test.

Fixes AE_NOT_EXIST error by including a conditional for the
EmbeddedControl which does not have a handler in the interpreter.

Also fixes AML_NO_RETURN_VALUE errors due the Derefof patch fix
by referencing the correct value that should be returned and checked
against by a Derefof operation.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>