ksmbd: validate smb request protocol id

This patch add the validation for smb request protocol id.
If it is not one of the four ids(SMB1_PROTO_NUMBER, SMB2_PROTO_NUMBER,
SMB2_TRANSFORM_PROTO_NUM, SMB2_COMPRESSION_TRANSFORM_ID), don't allow
processing the request. And this will fix the following KASAN warning
also.

[   13.905265] BUG: KASAN: slab-out-of-bounds in init_smb2_rsp_hdr+0x1b9/0x1f0
[   13.905900] Read of size 16 at addr ffff888005fd2f34 by task kworker/0:2/44
...
[   13.908553] Call Trace:
[   13.908793]  <TASK>
[   13.908995]  dump_stack_lvl+0x33/0x50
[   13.909369]  print_report+0xcc/0x620
[   13.910870]  kasan_report+0xae/0xe0
[   13.911519]  kasan_check_range+0x35/0x1b0
[   13.911796]  init_smb2_rsp_hdr+0x1b9/0x1f0
[   13.912492]  handle_ksmbd_work+0xe5/0x820

Cc: stable@vger.kernel.org
Reported-by: Chih-Yen Chang <cc85nod@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>