After-merge cleanups to alter_table test

mysql-test/r/alter_table.result

@@ -555,6 +555,7 @@ alter table test.t1 rename t1;
 ERROR 3D000: No database selected
 alter table test.t1 rename test.t1;
 use test;
+drop table t1;
 create table t1 (mycol int(10) not null);
 alter table t1 alter column mycol set default 0;
 desc t1;

mysql-test/t/alter_table.test

@@ -411,7 +411,7 @@ drop table t1;
 create table t1 (mycol int(10) not null);
 alter table t1 alter column mycol set default 0;
 desc t1;
-drop table;
+drop table t1;
 
 #
 # Some additional tests for new, faster alter table.  Note that most of the