x86/traps: Drop use_error_code parameter from do_{,guest_}trap()

x86/traps: Drop use_error_code parameter from do_{,guest_}trap()

Whether or not an error code is needed can be determinted entirely from the
trapnr paramter, as error codes are architecturally specified.

Introduce TRAP_HAVE_EC as a bitmap of reserved vectors which have error codes,
and drop the use_error_code from all callsites.

As a result, the DO_ERROR{,_NOCODE}() macros become entirely superflouous and
can be dropped.  Update the exception_table to point straight at do_trap().

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>