[CIFS] Print better error when server returns malformed QueryUnixInfo response

Signed-off-by: NSteve French <sfrench@us.ibm.com>

fs/cifs/cifssmb.c

@@ -3361,6 +3361,9 @@ CIFSSMBUnixQPathInfo(const int xid, struct cifsTconInfo *tcon,
 		rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
 		if (rc || (pSMBr->ByteCount < sizeof(FILE_UNIX_BASIC_INFO))) {
+			cERROR(1, ("Malformed FILE_UNIX_BASIC_INFO response.\n"
+				   "Unix Extensions can be disabled on mount "
+				   "by specifying the nosfu mount option."));
 			rc = -EIO;	/* bad smb */
 		} else {
 			__u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);