Fix an incorrect debug assertion

storage/innobase/include/page0zip.ic

@@ -2,6 +2,7 @@
 
 Copyright (c) 2005, 2013, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -172,7 +173,8 @@ page_zip_rec_needs_ext(
 				ignored if zip_size == 0 */
 	ulint	zip_size)	/*!< in: compressed page size in bytes, or 0 */
 {
-	ut_ad(rec_size > comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES);
+	ut_ad(rec_size
+	      > (comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES));
 	ut_ad(ut_is_2pow(zip_size));
 	ut_ad(comp || !zip_size);
 

storage/xtradb/include/page0zip.ic

@@ -2,6 +2,7 @@
 
 Copyright (c) 2005, 2013, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -172,7 +173,8 @@ page_zip_rec_needs_ext(
 				ignored if zip_size == 0 */
 	ulint	zip_size)	/*!< in: compressed page size in bytes, or 0 */
 {
-	ut_ad(rec_size > comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES);
+	ut_ad(rec_size
+	      > (comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES));
 	ut_ad(ut_is_2pow(zip_size));
 	ut_ad(comp || !zip_size);