xfs: merge xfs_reclaim_inodes_ag into xfs_inode_walk_ag

mainline-inclusion
from mainline-v5.13-rc4
commit f1bc5c56
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f1bc5c5630f90b83b339e8970dcf6d03abba5bd5



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Merge these two inode walk loops together, since they're pretty similar
now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Lihong Kou <koulihong@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>