Improve loop device setup for enhanced compatibility

scripts/debootstrap.sh

@@ -644,13 +644,11 @@ PREPARE_IMAGE_SIZE
 
 	check_loop_device "$LOOP"
 
-	losetup $LOOP ${SDCARD}.raw
+	losetup -P $LOOP ${SDCARD}.raw
 
 	# loop device was grabbed here, unlock
 	flock -u $FD
 
-	partprobe $LOOP
-
 	# stage: create fs, mount partitions, create fstab
 	rm -f $SDCARD/etc/fstab
 	if [[ -n $rootpart ]]; then