do clean-up of intermediate files at the end

Outside any specific stages, mostly because stages could potentially
share files.

Changelog: None

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

mender-convert

@@ -409,10 +409,6 @@ do_make_sdimg_raspberrypi3() {
   ((step++))
   set_fstab $device_type
 
-  [[ $keep != "-k" ]] && { rm -f $output_dir/boot.vfat\
-     $output_dir/cmdline.txt  $output_dir/config.txt\
-     $output_dir/rootfs.img; }
-
   return 0
 }
 
@@ -460,9 +456,6 @@ do_make_sdimg_qemux86_64() {
   ((step++))
   set_fstab $device_type
 
-  [[ $keep != "-k" ]] && { rm -f $output_dir/boot.vfat\
-     $output_dir/syslinux.cfg $output_dir/rootfs.img; }
-
   return 0
 }
 
@@ -885,4 +878,8 @@ case "$1" in
     ;;
 esac
 
+[[ $keep != "-k" ]] && { rm -f $output_dir/boot.vfat \
+      $output_dir/cmdline.txt $output_dir/config.txt \
+      $output_dir/syslinux.cfg $output_dir/rootfs.img; }
+
 exit 0