x86/retpolines: Enable the default thunk warning only on relevant configs

The using-default-thunk warning check makes sense only with
configurations which actually enable the special return thunks.

Otherwise, it fires on unrelated 32-bit configs on which the special
return thunks won't even work (they're 64-bit only) and, what is more,
those configs even go off into the weeds when booting in the
alternatives patching code, leading to a dead machine.

Fixes: 4461438a8405 ("x86/retpoline: Ensure default return thunk isn't used at runtime")
Reported-by: Klara Modin <[email protected]>
Reported-by: Erhard Furtner <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Tested-by: Klara Modin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/20240413024956.488d474e@yea

0 files changed, 0 insertions, 0 deletions