TLS backend OpenSSL: Use function-static variable for symbol loading

Replace a combination of a mutex, atomic variable, and another variable
by a function-local variable initialized by lambda.

C++17 standard guarantees that the lambda is called only once and
that any other callers will waiting for initialization to complete.

Task-number: QTBUG-103559
Change-Id: If9af8584e648ddb9ec518498ce035105e52413a2
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

0 files changed, 0 insertions, 0 deletions