Remove deadlock that was caused by calling pthread_rwlock_wrlock() on same thread twice. This can be reproduce only with musl.

CLA: trivial
Signed-off-by: NMatus Kysel <mkysel@tachyum.com>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10501)