elf: Disable most of TLS modid gaps processing [BZ #27135]

Revert "elf: Fix DTV gap reuse logic [BZ #27135]"

This reverts commit 572bd547.

It turns out that the _dl_next_tls_modid in _dl_map_object_from_fd keeps
returning the same modid over and over again if there is a gap and
more than TLS-using module is loaded in one dlopen call.  This corrupts
TLS data structures.  The bug is still present after a revert, but
empirically it is much more difficult to trigger (because it involves a
dlopen failure).