x86/mce: sanitise the #MC entry path

x86/mce: sanitise the #MC entry path

The 'error_code' function parameters are not used at all; drop it from the
call chain.  If it is needed at some point in the future, it is available via
cpu_user_regs.

Having do_machine_check() call the non-inlineable machine_check_vector() just
to get at the static function pointer '_machine_check_vector' is silly.  Move
do_machine_check() from traps.c to mce.c and do away with
machine_check_vector() entirely.

Both {intel,amd}_init_mce() register their own local function as the #MC
handler, each of which call mcheck_cmn_handler() in an identical way.  Fix
this craziness by actually turning mcheck_cmn_handler() into a valid #MC
handler (as its comments already state), and have {intel,amd}_init_mce()
register it instead of their own private handlers.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christoph Egger <chegger@amazon.de>