package/eudev: fix install command

The directory $(TARGET_DIR)/etc/init.d/ must exist before installing
S10udev init script.
Add the missing "-D" option to create the "init.d" directory.

Signed-off-by: Romain Naour <romain.naour@openwide.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>