As pointed out by wli, all other compilation relies on fixdep to
exist already.

BTW, wli's benchmark numbers for the kallsyms speed-up patch:

-make -j bzImage  323.03s user 157.65s system  843% cpu 57.019 total
+make -j bzImage  270.02s user 147.01s system 1303% cpu 32.004 total