mkinitfs.trigger should delete unused initramfs images

Everytime I upgrade the kernel, a new initramfs is created, but those never get deleted. Since they 4-7MB each, they can start to accumulate disk space. The mkinitfs.trigger should delete the initramfs images for which there is no kernel image.

(from redmine: issue id 660, created on 2011-05-25, closed on 2011-06-06)

• Changesets:
  • Revision 4ad9349a on 2011-06-01T08:44:33Z:

main/mkinitfs: delete unused initramfs images

ref #660

• Revision 702cc95c on 2011-06-03T18:58:58Z:

main/mkinitfs: delete unused initramfs images

fixes #660
(cherry picked from commit 4ad9349a4135087214c6ca5170d7faaebc29e796)