mm: simplify parameter of setup_usemap()

Parameter 'zone' has got needed information, let's remove other
unnecessary parameters.

Link: https://lkml.kernel.org/r/20210122135956.5946-5-bhe@redhat.com


Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>