do not fail conversion in disk_image_shrink_rootfs

That is if it fails, proceed with conversion without it.

The current logic only supports shrinking a rootfs on BBB and RPi
devices (this is deducted from $raw_disk_counts) and calling
'disk_image_shrink_rootfs' would fail on 'qemux86_64' device.

Shrinking the rootfs is not a hard-requirement and is only an
optimization (mainly for RPi devices).

Changelog: None

Signed-off-by: Mirza Krak <mirza.krak@northern.tech>

mender-convert

@@ -150,8 +150,8 @@ do_raw_disk_image_shrink_rootfs() {
   elif [[ $raw_disk_counts -eq 2 ]]; then
     sudo losetup $loopdevice $raw_disk_image -o $((${raw_disk_sizes[prootfs_start]} * $sector_size))
   else
-    log "Error: invalid/unsupported embedded raw disk image. Aborting."
+    log "Warning: invalid/unsupported embedded raw disk image. Skipping resize..."
-    return 1
+    return 0
   fi
 
   block_size=($(sudo dumpe2fs -h $loopdevice | grep 'Block size' | tr -s ' ' | cut -d ' ' -f3))