Remove bogus tracepoint
Calls to LWLockWaitForVar() fired the TRACE_POSTGRESQL_LWLOCK_ACQUIRE
tracepoint, but LWLockWaitForVar() never actually acquires the LWLock.
(Probably a copy/paste bug in
68a2e52bbaf.) Remove it.
Author: Craig Ringer <craig.ringer@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/CAGRY4nxJo+-HCC2i5H93ttSZ4gZO-FSddCwvkb-qAfQ1zdXd1w@mail.gmail.com