VFS: Rolling Back the fmode macro definition and structure members

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8O4U8


CVE: NA

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The readahead feature of the openEuler-22.03-LTS ebpf enhancement
involves interface changes and needs to be compatible with the ebpf
tool of openEuler-1.0-LTS. This patch changes the _ctl_mode to _mode of
fs_file_read_ctx structure.

Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>