InnoDB: Win64 portability fix: add missing declaration and

correct the definition of srv_max_buf_pool_modified_pct.

innobase/include/srv0srv.h

@@ -101,6 +101,7 @@ extern ibool	srv_use_doublewrite_buf;
 extern ibool    srv_set_thread_priorities;
 extern int      srv_query_thread_priority;
 
+extern ulong	srv_max_buf_pool_modified_pct;
 extern ulong	srv_max_purge_lag;
 /*-------------------------------------------*/
 

innobase/srv/srv0srv.c

@@ -165,7 +165,7 @@ in the buffer pool to all database pages in the buffer pool smaller than
 the following number. But it is not guaranteed that the value stays below
 that during a time of heavy update/insert activity. */
 
-ulint	srv_max_buf_pool_modified_pct	= 90;
+ulong	srv_max_buf_pool_modified_pct	= 90;
 
 /* If the following is != 0 we do not allow inserts etc. This protects
 the user from forgetting the innodb_force_recovery keyword to my.cnf */