mm/sharepool: Move comm from sp_proc_stat to sp_group_master.

hulk inclusion
category: other
bugzilla: https://gitee.com/openeuler/kernel/issues/I6ET9W



----------------------------------------------

comm is not memory usage information and
should not be stored in sp_proc_stat.

Signed-off-by: Xu Qiang <xuqiang36@huawei.com>