depmod: unconditionally write builtin.alias.bin
depmod: unconditionally write builtin.alias.bin

The file is always created and unless we return an error, the temporary
file is renamed to its final destination. All other places write the
index without checking if the index is empty, so just do the same.

Reported-by: Joe Buehler <d5a6a67e2e44a50c08e596bed087283503cccbc1@cox.net>

lucasdemarchi/kmod,lucasdemarchi/kmod,lucasdemarchi/kmod