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.
Before this fix, the performance schema tables were defined in UPPERCASE.
This was incompatible with the lowercase_table_names option, and caused
issues with the install / upgrade process, when changing the lower case
table names setting *after* the install or upgrade.
With this fix, all performance schema tables are exposed with lowercase names.
As a result, the name of the performance schema table is always lowercase,
no matter how / if / when the lowercase_table_names setting if changed.
