bpftool: Remove unnecessary source files from bootstrap version

Commit d510296d ("bpftool: Use syscall/loader program in "prog load"
and "gen skeleton" command.") added new files to the list of objects to
compile in order to build the bootstrap version of bpftool. As far as I
can tell, these objects are unnecessary and were added by mistake; maybe
a draft version intended to add support for loading loader programs from
the bootstrap version. Anyway, we can remove these object files from the
list to make the bootstrap bpftool binary a tad smaller and faster to
build.

Fixes: d510296d ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.")
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Message-ID: <20240320013457.44808-1-qmo@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>