NFSv4: fix open failure with O_ACCMODE flag

mainline inclusion
from mainline-v5.18-rc2
commit b243874f
category: bugfix
bugzilla: 186890, https://gitee.com/openeuler/kernel/issues/I5BZTX


CVE: NA

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

open() with O_ACCMODE|O_DIRECT flags secondly will fail.

Reproducer:
  1. mount -t nfs -o vers=4.2 $server_ip:/ /mnt/
  2. fd = open("/mnt/file", O_ACCMODE|O_DIRECT|O_CREAT)
  3. close(fd)
  4. fd = open("/mnt/file", O_ACCMODE|O_DIRECT)

Server nfsd4_decode_share_access() will fail with error nfserr_bad_xdr when
client use incorrect share access mode of 0.

Fix this by using NFS4_SHARE_ACCESS_BOTH share access mode in client,
just like firstly opening.

Fixes: ce4ef7c0 ("NFS: Split out NFS v4 file operations")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

conflict:
	fs/nfs/internal.h

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Reviewed-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>