jail: elf: Remove MIPS 64 warning

jail: elf: Remove MIPS 64 warning

Revert commit 33b799b ("ujail: elf: work around GCC bug on MIPS64")

The procd jails are working fine on MIPS64 too now.

I saw this error message when add_path_and_deps() was called which calls
elf_load_deps() again under some conditions. This is happening because
gcc_mips64_bug_work_around is stored in the data segment.

We have a call trace like this:
elf_load_deps()
  gcc_mips64_bug_work_around = 1;
  call add_path_and_deps()
    call elf_load_deps()
      gcc_mips64_bug_work_around = 1;
      error if gcc_mips64_bug_work_around =! 1
      gcc_mips64_bug_work_around = 0;
      return;
    return;
  error if gcc_mips64_bug_work_around =! 1
  return;

I got the same error messages on MIPS 32 BE, when I removed the compile
check.

This was tested in qemu on MIPS 64 BE and MIPS64 LE.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>