kbuild: Do not package /boot and /lib in make tar-pkg

There were reports of users destroying their Fedora installs by a kernel
tarball that replaces the /lib -> /usr/lib symlink. Let's remove the
toplevel directories from the tarball to prevent this from happening.

Reported-by: Andi Kleen <andi@firstfloor.org>
Suggested-by: Ben Hutchings <ben@decadent.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/package/buildtar

@@ -109,7 +109,7 @@ esac
 	if tar --owner=root --group=root --help >/dev/null 2>&1; then
 		opts="--owner=root --group=root"
 	fi
-	tar cf - . $opts | ${compress} > "${tarball}${file_ext}"
+	tar cf - boot/* lib/* $opts | ${compress} > "${tarball}${file_ext}"
 )
 
 echo "Tarball successfully created in ${tarball}${file_ext}"