in mysql_creata_like_table() we 'downcase' the complete path to the
.frm file. It works fine in standalone case as there usually
we only have './' as a path to the datahome, but doesn't work in
the embedded server where we add the real path there, so if a
directory has uppercase letters in it's name, it won't be found.

Fixed by 'downcasing' only database/table pair.