Fixed compiler warnings.

sql/sql_lex.cc

@@ -3239,7 +3239,7 @@ void st_select_lex::append_table_to_list(TABLE_LIST *TABLE_LIST::*link,
                                          TABLE_LIST *table)
 {
   TABLE_LIST *tl;
-  for (tl= leaf_tables.head(); tl->*link; tl= tl->*link);
+  for (tl= leaf_tables.head(); tl->*link; tl= tl->*link) ;
   tl->*link= table;
 }
 

sql/sql_select.cc

@@ -7793,10 +7793,10 @@ bool generate_derived_keys(DYNAMIC_ARRAY *keyuse_array)
   TABLE *prev_table= 0;
   for (uint i= 0; i < elements; i++, keyuse++)
   {
-    KEYUSE *first_table_keyuse;
-    table_map last_used_tables;
-    uint count;
-    uint keys;
+    KEYUSE *first_table_keyuse= NULL;
+    table_map last_used_tables= 0;
+    uint count= 0;
+    uint keys= 0;
     TABLE_LIST *derived= NULL;
     if (keyuse->table != prev_table)
       derived= keyuse->table->pos_in_table_list;

sql/sql_union.cc

@@ -356,8 +356,8 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
     List_iterator_fast<Item> tp(types);
     Item *type;
     ulonglong create_options;
-    uint save_tablenr;
-    table_map save_map;
+    uint save_tablenr= 0;
+    table_map save_map= 0;
 
     while ((type= tp++))
     {