testing: Use blockdev instead of partprobe to load partitions

This avoids a dependency on parted as blockdev is in util-linux on
Debian/Ubuntu, which is installed by default.  And it might work more
reliably.

testing/scripts/build-baseimage

@@ -9,7 +9,7 @@ DIR=$(dirname `readlink -f $0`)
 [ `id -u` -eq 0 ] || die "You must be root to run $0"
 running_any $STRONGSWANHOSTS && die "Please stop test environment before running $0"
 
-check_commands debootstrap mkfs.ext3 partprobe qemu-img qemu-nbd sfdisk
+check_commands debootstrap mkfs.ext3 blockdev qemu-img qemu-nbd sfdisk
 
 # package includes/excludes
 INC=automake,autoconf,libtool,bison,flex,gperf,pkg-config,gettext,less,locales
@@ -97,7 +97,7 @@ then
 else
 	log_status 0
 fi
-partprobe $NBDEV
+blockdev --rereadpt $NBDEV
 
 log_action "Creating ext3 filesystem"
 execute "mkfs.ext3 $NBDPARTITION"