This reverts commit 81b83ff61f to move
__xmknod{at} back to default symbols. ABIs with default symbol version
of 2.33 or newer (such as riscv32) continue to just provide the mknod*
symbols.
The idea is to not force static libraries built against old glibc
to update against new glibcs (since they reference the the
xmknod{at} symbols).
Checked on x86_64-linux-gnu and i686-linux-gnu.
f147616d68