x86/smpboot: Remove redundant order calculations

x86/smpboot: Remove redundant order calculations

The GDT and IDT allocations are all order 0, and not going to change.

Use an explicit 0, instead of calling get_order_from_pages().  This
allows for the removal of the 'order' local parameter in both
cpu_smpboot_{alloc,free}().

While making this adjustment, rearrange cpu_smpboot_free() to fold the
two "if ( remove )" clauses.  There is no explicit requirements for the
order of free()s.

No practical change.

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