ksmbd: fix wrong compression context size

mainline inclusion
from mainline-5.15-rc1
commit e4b60e92
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I60T7G
CVE: NA

Reference: https://git.kernel.org/torvalds/linux/c/e4b60e92d4f8



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Use smb2_compression_ctx instead of smb2_encryption_neg_context.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>