fixed error processing of prepare in VIEW creation (BUG#4801)

mysql-test/r/view.result:
  test of error processing found in preparation phase
mysql-test/t/view.test:
  test of error processing found in preparation phase
sql/sql_view.cc:
  fixed error processing of prepare

mysql-test/r/view.result

@@ -1036,3 +1036,9 @@ a
 4
 drop view v1;
 drop table t1;
+CREATE VIEW v02 AS SELECT * FROM DUAL;
+ERROR HY000: No tables used
+SHOW TABLES;
+Tables_in_test	table_type
+t2	BASE TABLE
+v4	VIEW

mysql-test/t/view.test

@@ -973,3 +973,10 @@ select * from t1;
 
 drop view v1;
 drop table t1;
+
+#
+# error on preparation
+#
+-- error 1096
+CREATE VIEW v02 AS SELECT * FROM DUAL;
+SHOW TABLES;

sql/sql_view.cc

@@ -183,8 +183,15 @@ int mysql_create_view(THD *thd,
 
   // prepare select to resolve all fields
   lex->view_prepare_mode= 1;
-  if ((res= unit->prepare(thd, 0, 0)))
+  if (unit->prepare(thd, 0, 0))
+  {
+    /*
+      some errors from prepare are reported to user, if is not then
+      it will be checked after err: label
+    */
+    res= 1;
     goto err;
+  }
 
   /* view list (list of view fields names) */
   if (lex->view_list.elements)