Changed mysql-test to print warnings for not existing table to DROP TABLE

Cleaned up test; Removed wrong DROP TABLE commands and use standard table and database names.
changed store_warning() -> push_warning_print()

mysql-test/t/truncate.test

@@ -1,7 +1,10 @@
 #
 # Test of truncate
 #
+--disable_warnings
 drop table if exists t1;
+--enable_warnings
+
 create table t1 (a integer, b integer,c1 CHAR(10));
 insert into t1 (a) values (1),(2);
 truncate table t1;