image-live.bbclass: optional depends when ROOTFS empty

`ROOTFS` is optional. It can be empty if the live image doesn't require
a rootfs.  In such cases, the build doesn't depend on
`do_image_{LIVE_ROOTFS_TYPE}`.

(From OE-Core rev: f1dda70ff8b672b695b44079db69a0563bb6c96c)

Signed-off-by: Guillaume Champagne <champagne.guillaume.c@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 96f47c39f1d17f073243913d524bde84add41d8f)
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/meta/classes/image-live.bbclass b/meta/classes/image-live.bbclass
index 54058b350d..e9eba1fc4b 100644
--- a/meta/classes/image-live.bbclass
+++ b/meta/classes/image-live.bbclass
@@ -30,7 +30,7 @@ do_bootimg[depends] += "dosfstools-native:do_populate_sysroot \
                         virtual/kernel:do_deploy \
                         ${MLPREFIX}syslinux:do_populate_sysroot \
                         syslinux-native:do_populate_sysroot \
-                        ${PN}:do_image_${@d.getVar('LIVE_ROOTFS_TYPE').replace('-', '_')} \
+                        ${@'%s:do_image_%s' % (d.getVar('PN'), d.getVar('LIVE_ROOTFS_TYPE').replace('-', '_')) if d.getVar('ROOTFS') else ''} \
                         "