image.bbclass: create device table after package installation

Now that the makedevs supports using user/group names in the devcie
table files, and it uses passwd and group files under the rootfs which
is provided by the base-passwd package, we should let package installation
finish first, so that makedevs can get a correct mapping from user/group
names to uid/gid.

The check for existence of ${IMAGE_ROOTFS}/dev is removed. This is because
do_rootfs doesn't have 'nostamp' flag any more, so the do_rootfs task will
not be rerun for every build. Checking for the existence of ${IMAGE_ROOTFS}/dev
is not necessary any more. Besides, as base-files package also installs the
/dev directory, this checking does not serve as a good criteria.

[YOCTO #1159]

(From OE-Core rev: d073ca77ba886c7912abd3ec0640881c00aea3bb)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/image.bbclass

@@ -297,9 +297,9 @@ fakeroot do_rootfs () {
 	# copy the intercept scripts
 	cp ${COREBASE}/scripts/postinst-intercepts/* ${WORKDIR}/intercept_scripts/
 
-	# If "${IMAGE_ROOTFS}/dev" exists, then the device had been made by
-	# the previous build
-	if [ "${USE_DEVFS}" != "1" -a ! -r "${IMAGE_ROOTFS}/dev" ]; then
+	rootfs_${IMAGE_PKGTYPE}_do_rootfs
+
+	if [ "${USE_DEVFS}" != "1" ]; then
 		for devtable in ${@get_devtable_list(d)}; do
 			# Always return ture since there maybe already one when use the
 			# incremental image generation
@@ -307,8 +307,6 @@ fakeroot do_rootfs () {
 		done
 	fi
 
-	rootfs_${IMAGE_PKGTYPE}_do_rootfs
-
 	# remove unneeded packages/files from the final image
 	rootfs_remove_unneeded