MFC r345693, 345694: rtld: attempt to fix reloc_nonplt_object TLS allocation
on arm and mips
allocate_tls_offset returns true on success. This still needs more
testing and review, but this change is consistent with other archs.
PR: 236880
Reported by: Andrew Gierth <andrew@tao11.riddles.org.uk> (arm)
Sponsored by: The FreeBSD Foundation