tools: Use test/kmod instead of kmod-nolib

The reason to have a kmod-nolib binary is that we need to call kmod on
test cases (or a symlink to it) and for testing things in tree. Since
we are using libtool if we are dinamically linking to libkmod what we
end up having is a shell script that (depending on the version *)
changes argv[0] to contain an "lt-" prefix. Since this screws with our
compat stuff, we had a kmod-nolib that links statically.

This all workaround works fine iff we are using one of the compat
commands, i.e. we are using the symlinks insmod, rmmod, modprobe, etc.
However if we are actually trying the kmod binary, this doesn't work
because we can't create a kmod symlink since there's already a kmod
binary.

So, completely give up on libtool fixing their mess. Now we create a
tool/test/ directory and the symlinks and kmod is put there.

* http://lists.gnu.org/archive/html/bug-libtool/2011-12/msg00023.html