Fix asan finding in bio_addr

Fix asan finding in bio_addr

Running test_tfo_cli under asan yields
==166214==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60700000d57c at pc 0x03ffa004ed86 bp 0x03ffe2977e80 sp 0x03ffe2977668
READ of size 112 at 0x60700000d57c thread T0
    #0 0x3ffa004ed85 in memcpy (/lib64/libasan.so.8+0x4ed85)
    #1 0x3ff9f3615b7 in BIO_ADDR_dup crypto/bio/bio_addr.c:77
[...]
and fails the test.

Fix this by copying the right structure of the union.

Signed-off-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Todd Short <todd.short@me.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18979)