BUG#25303 log_state fails

sql/set_var.cc:
  BUG#25303 opt_slow_log is really a my_bool

sql/set_var.cc

@@ -875,7 +875,7 @@ SHOW_VAR init_vars[]= {
 #ifdef HAVE_REPLICATION
   {"log_slave_updates",       (char*) &opt_log_slave_updates,       SHOW_MY_BOOL},
 #endif
-  {"log_slow_queries",        (char*) &opt_slow_log,                SHOW_BOOL},
+  {"log_slow_queries",        (char*) &opt_slow_log,                SHOW_MY_BOOL},
   {sys_log_warnings.name,     (char*) &sys_log_warnings,	    SHOW_SYS},
   {sys_long_query_time.name,  (char*) &sys_long_query_time, 	    SHOW_SYS},
   {sys_low_priority_updates.name, (char*) &sys_low_priority_updates, SHOW_SYS},