Revert "mm/mempolicy: don't handle MPOL_LOCAL like a fake MPOL_PREFERRED policy"

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8PGB8


CVE: NA

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This reverts commit d634f94d.

Revert this commit due to perf issue.

Introduce mpol_rebind_preferred_many to make rebind logic for
MPOL_PREFERRED_MANY right.

Make __mpol_equal to check nodes rather than preferred_node for
MPOL_PREFERRED_MANY to make logic right.

Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>