ksmbd: use ksmbd_req_buf_next() in ksmbd_smb2_check_message()

Use ksmbd_req_buf_next() in ksmbd_smb2_check_message().

Cc: Tom Talpey <tom@talpey.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/smb2misc.c

@@ -347,17 +347,12 @@ static int smb2_validate_credit_charge(struct ksmbd_conn *conn,
 
 int ksmbd_smb2_check_message(struct ksmbd_work *work)
 {
-	struct smb2_pdu *pdu = work->request_buf;
+	struct smb2_pdu *pdu = ksmbd_req_buf_next(work);
 	struct smb2_hdr *hdr = &pdu->hdr;
 	int command;
 	__u32 clc_len;  /* calculated length */
 	__u32 len = get_rfc1002_len(pdu);
 
-	if (work->next_smb2_rcv_hdr_off) {
-		pdu = ksmbd_req_buf_next(work);
-		hdr = &pdu->hdr;
-	}
-
 	if (le32_to_cpu(hdr->NextCommand) > 0) {
 		len = le32_to_cpu(hdr->NextCommand);
 	} else if (work->next_smb2_rcv_hdr_off) {