This is a code cleanup.

The implementation of a storage engine (subclasses of handler) is not supposed
to call my_error() directly inside the engine implementation, 
but only return error codes, and report errors later at the demand
of the sql layer only (if needed), using handler::print_error().

This fix removes misplaced calls to my_error(),
and provide an implementation of print_error() instead.

Given that the sql layer implementation of create table, ha_create_table(),
does not use print_error() but returns ER_CANT_CREATE_TABLE directly,
the return code for create table statements using the performance schema
has changed to ER_CANT_CREATE_TABLE.

Adjusted the test suite accordingly.