rootfs_deb: Update IMAGE_ROOTFS variable usage to be consistent
rootfs_deb: Update IMAGE_ROOTFS variable usage to be consistent

update IMAGE_ROOTFS variable to fix inconsistent use of IMAGE_ROOTFS variable
content in by apt-native after the changes introducd in
2343808f7386cbd4c7b43f1b24e65e173f5ddf15.  This commit changed IMAGE_ROOTFS
from "${TMPDIR}/rootfs" to "${TMPDIR}/rootfs/${PN}" and that caused
IMAGE_ROOTFS to expand to ${TMPDIR}/rootfs/apt-native in apt.conf.sample,
however rootfs_deb.class uses apt.conf.sample to generate apt-rootfs.conf and
here here IMAGE_ROOTFS is different from that in apt-native package.

Acked-by: Tom Rini <47764aff062bf9ebe98a2274b29052b74a9567e2@embeddedaley.com>

sentient-energy/emsw-oe-mirror,nx111/openembeded_openpli2.1_nx111,sampov2/audio-openembedded,JamesAng/goe,bticino/openembedded,openpli-arm/openembedded,dave-billin/overo-ui-moos-auv,John-NY/overo-oe,John-NY/overo-oe,openpli-arm/openembedded,dellysunnymtech/sakoman-oe,BlackPole/bp-openembedded,dave-billin/overo-ui-moos-auv,anguslees/openembedded-android,thebohemian/openembedded,dave-billin/overo-ui-moos-auv,crystalfontz/openembedded,sledz/oe,JamesAng/oe,sledz/oe,bticino/openembedded,Martix/Eonos,sentient-energy/emsw-oe-mirror,sutajiokousagi/openembedded,sledz/oe,sampov2/audio-openembedded,rascalmicro/openembedded-rascal,xifengchuo/openembedded,BlackPole/bp-openembedded,rascalmicro/openembedded-rascal,anguslees/openembedded-android,openembedded/openembedded,John-NY/overo-oe,dellysunnymtech/sakoman-oe,yyli/overo-oe,dellysunnymtech/sakoman-oe,thebohemian/openembedded,yyli/overo-oe,xifengchuo/openembedded,rascalmicro/openembedded-rascal,openembedded/openembedded,xifengchuo/openembedded,JamesAng/oe,sledz/oe,anguslees/openembedded-android,sentient-energy/emsw-oe-mirror,libo/openembedded,yyli/overo-oe,philb/pbcl-oe-2010,scottellis/overo-oe,openembedded/openembedded,hulifox008/openembedded,sutajiokousagi/openembedded,BlackPole/bp-openembedded,JamesAng/goe,sledz/oe,yyli/overo-oe,buglabs/oe-buglabs,scottellis/overo-oe,mrchapp/arago-oe-dev,bticino/openembedded,philb/pbcl-oe-2010,thebohemian/openembedded,sentient-energy/emsw-oe-mirror,sutajiokousagi/openembedded,buglabs/oe-buglabs,xifengchuo/openembedded,openembedded/openembedded,rascalmicro/openembedded-rascal,anguslees/openembedded-android,buglabs/oe-buglabs,JamesAng/goe,buglabs/oe-buglabs,crystalfontz/openembedded,dellysunnymtech/sakoman-oe,openembedded/openembedded,openembedded/openembedded,xifengchuo/openembedded,openembedded/openembedded,nzjrs/overo-openembedded,yyli/overo-oe,hulifox008/openembedded,JamesAng/oe,hulifox008/openembedded,bticino/openembedded,mrchapp/arago-oe-dev,libo/openembedded,scottellis/overo-oe,crystalfontz/openembedded,scottellis/overo-oe,bticino/openembedded,JamesAng/oe,dave-billin/overo-ui-moos-auv,JamesAng/goe,John-NY/overo-oe,SIFTeam/openembedded,nzjrs/overo-openembedded,Martix/Eonos,giobauermeister/openembedded,JamesAng/oe,rascalmicro/openembedded-rascal,dave-billin/overo-ui-moos-auv,libo/openembedded,giobauermeister/openembedded,Martix/Eonos,trini/openembedded,xifengchuo/openembedded,hulifox008/openembedded,sentient-energy/emsw-oe-mirror,JamesAng/oe,mrchapp/arago-oe-dev,openembedded/openembedded,hulifox008/openembedded,sentient-energy/emsw-oe-mirror,buglabs/oe-buglabs,buglabs/oe-buglabs,SIFTeam/openembedded,BlackPole/bp-openembedded,John-NY/overo-oe,mrchapp/arago-oe-dev,John-NY/overo-oe,sampov2/audio-openembedded,Martix/Eonos,buglabs/oe-buglabs,trini/openembedded,thebohemian/openembedded,giobauermeister/openembedded,SIFTeam/openembedded,rascalmicro/openembedded-rascal,xifengchuo/openembedded,sutajiokousagi/openembedded,hulifox008/openembedded,nx111/openembeded_openpli2.1_nx111,sutajiokousagi/openembedded,anguslees/openembedded-android,nx111/openembeded_openpli2.1_nx111,scottellis/overo-oe,trini/openembedded,nzjrs/overo-openembedded,Martix/Eonos,sledz/oe,nzjrs/overo-openembedded,giobauermeister/openembedded,sentient-energy/emsw-oe-mirror,anguslees/openembedded-android,sampov2/audio-openembedded,crystalfontz/openembedded,openembedded/openembedded,nx111/openembeded_openpli2.1_nx111,JamesAng/goe,openpli-arm/openembedded,SIFTeam/openembedded,dellysunnymtech/sakoman-oe,philb/pbcl-oe-2010,dellysunnymtech/sakoman-oe,mrchapp/arago-oe-dev,yyli/overo-oe,libo/openembedded,libo/openembedded,thebohemian/openembedded,sutajiokousagi/openembedded,xifengchuo/openembedded,BlackPole/bp-openembedded,JamesAng/goe,sledz/oe,sutajiokousagi/openembedded,trini/openembedded,dellysunnymtech/sakoman-oe,yyli/overo-oe,sampov2/audio-openembedded,hulifox008/openembedded,crystalfontz/openembedded,BlackPole/bp-openembedded,nx111/openembeded_openpli2.1_nx111,dave-billin/overo-ui-moos-auv,SIFTeam/openembedded,JamesAng/oe,bticino/openembedded,rascalmicro/openembedded-rascal,giobauermeister/openembedded,openembedded/openembedded,mrchapp/arago-oe-dev,bticino/openembedded,giobauermeister/openembedded,SIFTeam/openembedded,nx111/openembeded_openpli2.1_nx111,libo/openembedded,crystalfontz/openembedded,openpli-arm/openembedded,nzjrs/overo-openembedded,thebohemian/openembedded,trini/openembedded,scottellis/overo-oe,giobauermeister/openembedded,Martix/Eonos,anguslees/openembedded-android,giobauermeister/openembedded,libo/openembedded,crystalfontz/openembedded,nx111/openembeded_openpli2.1_nx111,sampov2/audio-openembedded,openembedded/openembedded,dellysunnymtech/sakoman-oe,philb/pbcl-oe-2010,dave-billin/overo-ui-moos-auv,nzjrs/overo-openembedded,thebohemian/openembedded,sampov2/audio-openembedded,philb/pbcl-oe-2010,SIFTeam/openembedded,rascalmicro/openembedded-rascal,philb/pbcl-oe-2010,Martix/Eonos,buglabs/oe-buglabs,BlackPole/bp-openembedded,openpli-arm/openembedded,mrchapp/arago-oe-de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