Simplify some conditions related to [LW]Lock in generate-wait_event_types.pl
The first check on the enum values was not necessary as the values set
in wait_event_names.txt for the classes LWLock and Lock were able to
satisfy the check. The second check when generating the C and header
files is now based on a match of the class names, making it simpler to
understand.
Author: Masahiro Ikeda, Michael Paquier
Discussion: https://postgr.es/m/
eaf82a85c0ef1b55dc3b651d3f7b867a@oss.nttdata.com