x86, mpparse: Remove unnecessary variable

'ret' isn't used by check_slot(), gets initialized but has no real use,
so remove it.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
LKML-Reference: <AANLkTikh3y+is3xixKBdyHhr_cHxzPFJF729Fcvt8+Ns@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>