It is done for the same reasons as 4243afdb does it for builddeb:
always runs make modules to install modules.builtin* files, which are
needed for e.g. initramfs-tools or LTP testing tool.
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>