smb: minor fix to use SMB2_NTLMV2_SESSKEY_SIZE for auth_key size

Replaced hardcoded value 16 with SMB2_NTLMV2_SESSKEY_SIZE
in the auth_key definition and memcpy call.

Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: bharathsm-ms

fs/smb/client/cifs_ioctl.h

@@ -61,7 +61,7 @@ struct smb_query_info {
 struct smb3_key_debug_info {
 	__u64	Suid;
 	__u16	cipher_type;
-	__u8	auth_key[16]; /* SMB2_NTLMV2_SESSKEY_SIZE */
+	__u8	auth_key[SMB2_NTLMV2_SESSKEY_SIZE];
 	__u8	smb3encryptionkey[SMB3_SIGN_KEY_SIZE];
 	__u8	smb3decryptionkey[SMB3_SIGN_KEY_SIZE];
 } __packed;

fs/smb/client/ioctl.c

@@ -506,7 +506,7 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
 				le16_to_cpu(tcon->ses->server->cipher_type);
 			pkey_inf.Suid = tcon->ses->Suid;
 			memcpy(pkey_inf.auth_key, tcon->ses->auth_key.response,
-					16 /* SMB2_NTLMV2_SESSKEY_SIZE */);
+				  SMB2_NTLMV2_SESSKEY_SIZE);
 			memcpy(pkey_inf.smb3decryptionkey,
 			      tcon->ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
 			memcpy(pkey_inf.smb3encryptionkey,