ldso: fix calloc misuse allocating initial tls

ldso: fix calloc misuse allocating initial tls

this is analogous to commit 2f1f51ae7b2d78247568e7fdb8462f3c19e469a4,
and should have been caught at the same time since it was right next
to the code moved in that commit. between final stage 3 reloc_all and
the jump to the main program's entry point, it is not valid to call
any functions which may be interposed by the application; doing so
results in execution of application code before ctors have run, and on
fdpic archs, before the main program's fdpic self-fixups have taken
place, which will produce runaway wrong execution.