Use OPENSSL_free for OpenSSL allocations to avoid crash

[skmcgrail]

Description

OpenSSL functions, like X509_NAME_oneline, returns pointers to memory allocations created using OPENSSL_malloc. The documentation for OpenSSL hints that such allocations should be freed using OPENSSL_free and not the standard free. For example:

OPENSSL_strdup(), OPENSSL_strndup() and OPENSSL_memdup() are like the equivalent C functions, except that memory is allocated by calling the OPENSSL_malloc() and should be released by calling OPENSSL_free().

In OpenSSL forks like BoringSSL and AWS-LC, OPENSSL_malloc returns a pointer that can't be freed by free, and when attempted will cause a panic:

#0  0x0000ffff8e367c9c in free () from /lib64/libc.so.6
#1  0x000000000043a168 in tls_free_conninfo (conninfo=0x272fbea0) at lib/usual/tls/tls_conninfo.c:193
#2  0x0000000000436dc4 in tls_reset (ctx=ctx@entry=0x272f4bb0) at lib/usual/tls/tls.c:519
#3  0x0000000000436e58 in tls_free (ctx=0x272f4bb0) at lib/usual/tls/tls.c:494

This PR updates tls_free_conninfo to properly free the issuer and subject information in order to improve compatibility with the OpenSSL forks.