md: refactor action_store() for 'idle' and 'frozen'

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6T6VY


CVE: NA

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Prepare to handle 'idle' and 'frozen' differently to fix a deadlock, there
are no functional changes except that MD_RECOVERY_RUNNING is checked
again after 'reconfig_mutex' is held.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>