fil_create_new_single_table_tablespace(): Correct a bogus nonnull attribute

The parameter path can be passed as NULL.
This error was reported by GCC 7.1.0 when compiling
CMAKE_BUILD_TYPE=Debug with -O3.

storage/innobase/fil/fil0fil.cc

@@ -2271,14 +2271,12 @@ fil_op_log_parse_or_replay(
 		} else if (log_flags & MLOG_FILE_FLAG_TEMP) {
 			/* Temporary table, do nothing */
 		} else {
-			const char*	path = NULL;
-
 			/* Create the database directory for name, if it does
 			not exist yet */
 			fil_create_directory_for_tablename(name);
 
 			if (fil_create_new_single_table_tablespace(
-				    space_id, name, path, flags,
+				    space_id, name, NULL, flags,
 				    DICT_TF2_USE_TABLESPACE,
 				    FIL_IBD_FILE_INITIAL_SIZE) != DB_SUCCESS) {
 				ut_error;

storage/innobase/include/fil0fil.h

 /*****************************************************************************
 
 Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation. All Rights Reserved.
+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
@@ -782,7 +782,7 @@ fil_create_new_single_table_tablespace(
 	ulint		size)		/*!< in: the initial size of the
 					tablespace file in pages,
 					must be >= FIL_IBD_FILE_INITIAL_SIZE */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
+	MY_ATTRIBUTE((nonnull(2), warn_unused_result));
 #ifndef UNIV_HOTBACKUP
 /********************************************************************//**
 Tries to open a single-table tablespace and optionally checks the space id is

storage/xtradb/fil/fil0fil.cc

@@ -2323,14 +2323,12 @@ fil_op_log_parse_or_replay(
 		} else if (log_flags & MLOG_FILE_FLAG_TEMP) {
 			/* Temporary table, do nothing */
 		} else {
-			const char*	path = NULL;
-
 			/* Create the database directory for name, if it does
 			not exist yet */
 			fil_create_directory_for_tablename(name);
 
 			if (fil_create_new_single_table_tablespace(
-				    space_id, name, path, flags,
+				    space_id, name, NULL, flags,
 				    DICT_TF2_USE_TABLESPACE,
 				    FIL_IBD_FILE_INITIAL_SIZE) != DB_SUCCESS) {
 				ut_error;

storage/xtradb/include/fil0fil.h

 /*****************************************************************************
 
 Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation. All Rights Reserved.
+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
@@ -778,7 +778,7 @@ fil_create_new_single_table_tablespace(
 	ulint		size)		/*!< in: the initial size of the
 					tablespace file in pages,
 					must be >= FIL_IBD_FILE_INITIAL_SIZE */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
+	MY_ATTRIBUTE((nonnull(2), warn_unused_result));
 #ifndef UNIV_HOTBACKUP
 /********************************************************************//**
 Tries to open a single-table tablespace and optionally checks the space id is