libc dl_iterate_phdr(): dlpi_tls_data is wrong

This is the same change as d36d681615170590, but for libc static implementaion
of dl_iterate_phdr().

Reported by: emacsray@gmail.com
PR: 254774
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29623