mm, compaction: finish scanning the current pageblock if requested

cc->finish_pageblock is set when the current pageblock should be rescanned
but fast_find_migrateblock can select an alternative block.  Disable
fast_find_migrateblock when the current pageblock scan should be
completed.

Link: https://lkml.kernel.org/r/20230125134434.18017-4-mgorman@techsingularity.net


Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>