tools/docker: add ld.lld to syzbot
tools/docker: add ld.lld to syzbot

Now that we have the ability to specify the linker, make it possible to
choose between ld and ld.lld.

google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller